Combination therapy against stress-induced pathophysiology

Abstract

Provided herein include compounds, compositions, kits and methods for preventing and treating psychiatric disorders. The composition and methods described herein can prophylactically treat a subject prior to and / or after a stressor and / or prior to the recurrence of a stressor, thereby preventing or delaying a relapse of depression or depression-like and / or stress-induced behaviors and disorders. The composition can comprise a serotonin 4 receptor (S-HUR) agonist and an N- methyl-D-aspartate (NMDAR) antagonist and a pharmaceutically acceptable salt, analog, derivative or metabolite thereof.

Description

ATTORNEY REF. 44010.238WO / CU25161 / 72GJ-890002-WO PATENT COMBINATION THERAPY AGAINST STRESS-INDUCED PATHOPHYSIOLOGY RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 63 / 754,397, filed on February 5, 2025, and U.S. Provisional Patent Application Ser. No. 63 / 744,572, filed on January 13, 2025 the contents of these related applications are incorporated herein by reference in their entirety for all purposes.BACKGROUNDField

[0002] The present application generally relates to compositions and methods for preventing and treating psychiatric disorders.Description of the Related Art

[0003] Psychiatric disorders such as major depressive disorder (MDD) and treatmentresistant depression (TRD) remain significant clinical challenges, with many patients failing to achieve remission with current monotherapies. The lack of efficacy in nearly two-thirds of patients has driven the exploration of combinatorial treatment strategies that integrate pharmacological agents targeting complementary neural pathways. Numerous guidelines have been published indicating that combination treatment is recommended for patients with moderate-to-severe MDD, for elderly patients, women, and / or for patients with psychosocial or interpersonal problems. Combination therapies aim to capitalize on synergistic effects, enhance efficacy, and mitigate side effects. A growing body of research emphasizes the need for novel combinations that leverage recent insights into neuroplasticity, neurotransmitter systems, and circuit-level dysregulation in psychiatric disorders.

[0004] (A,5)-ketamine, an NMDAR antagonist, FDA-approved anesthetic, and rapid acting antidepressant has transformed the field of psychiatry in the last 20 years. Unlike classical antidepressants, (A,5)-ketamine produces effects within hours. (A,5)-ketamine alters synaptic plasticity, neurogenesis, neurotransmitters, and brain connectivity, but loses efficacy without repeating dosing. Therefore, there is much interest in identifying multimodality strategies that are safe and capable of prolonging the efficacy of (A,5)-ketamine. Efforts to harness (A,5)-ketamine’s benefits while addressing its limitations have spurred interest in combination therapies that enhance its therapeutic window and reduce adverse effects. 5-HT4R agonists represent another promising avenue in psychopharmacology. Known primarily for their gastrointestinal applications, 5-HT4R agonists such as prucalopride have demonstrated pro-cognitive and antidepressant-like effects in preclinical and clinical studies. Activation of S-FFURs enhanceshippocampal neurogenesis and modulates serotonergic signaling, mechanisms critical for mood and cognitive regulation. Unlike traditional serotonergic antidepressants, 5-HT4R agonists exhibit a rapid onset of action and minimal sedative effects, making them attractive candidates for combinatorial strategies. Early findings suggest that 5-HT4R agonists could potentiate the effects of other antidepressants, further supporting their inclusion in multi-target approaches.

[0005] Furthermore, according to clinical guidelines, pharmacological treatment for depression may be separated into distinct phases. During an acute depressive episode, treatment with an approved antidepressant medication in a responsive patient can allow for progression to full remission. Here, patients enter a continuation phase, in which medication is continuously administered for several months. Subsequently, patients may be gradually tapered off medication, as rapid discontinuation of treatment can lead to a symptomatic relapse. Regardless of adherence to these guidelines, the risk of relapse is extremely high, with an estimated rate of up to 60% of patients at risk of developing recurrent depressive episodes.

[0006] Therefore, there is a need for improved treatment therapy to prevent and treat a range of stress-induced psychiatric behaviors and disorders. In particular, the desired treatment therapy would not only lead to remission but also prevent future relapse of depressive episodes.SUMMARY

[0007] Disclosed herein include methods, compositions, and kits for preventing and treating psychiatric disorders. The present disclosure provides a method of preventing a relapse of a stress-induced behavior or disorder in a subject. The method can comprise administering to the subject an effective amount of (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and an effective amount of (2) an N-methyl-D-aspartate receptor (NMDAR) antagonist, a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the stress-induced behavior in the subject. In some embodiments, the stress-induced behavior or disorder comprises fear, behavioral despair, perseverative behaviors, depression or depressionlike behavior, and / or anxiety-like behavior.

[0008] The present disclosure also provide a method of preventing a relapse of a depression or depression-like behavior or disorder in a subject. The method can comprise administering to the subject an effective amount of a composition comprising (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, and (2) an N-methyl-D-aspartate receptor (NMDAR) antagonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the depression or depression-like behavior or disorder in the subject. The depression or depression-like behavior or disorder can be stress-induced or not stress-induced.

[0009] In some embodiments, the NMDAR antagonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof is ketamine or an analog, a derivative or a metabolite thereof. The ketamine or analog, derivative or metabolite thereof can be selected from the group consisting of: ( / / j-ketamine, (S)-ketamine, (7?,5)-ketamine, hydroxy ketamines, dehydronorketamine, (7?,5)-norketamine, (2 / ?,6 / ?)-hydroxynorketamine ((2 / ?,6 / ?)-HNI<), and (25,65)-hydroxynorketamine ((25,65)-HNK), (2 / ?,6 / ?;2 6,S')-HNI<, or a combination thereof. In some embodiments, the ketamine or an analog, a derivative or a metabolite is selected from the group consisting of: norketamine, hydroxy ketamines, dehydronorketamine, hydroxynorketamine, or a combination thereof. In some embodiments, the NMDAR antagonist is (2 / 6 / ?)-HNK.

[0010] In some embodiments, the 5-HT4R agonist comprises l-(4-amino-5-chloro-2-methoxyphenyl)-3-[l(n-butyl)-4-piperidinyl]-l-propanone HC1 (RS-67,333), 4-amino-5-chloro-2,3-dihydro-N-[l-3-methoxypropyl)-4-piperidinyl]-7-benzofuran carboxamide mono hydrochloride (prucalopride), 4-[4-[4-Tetrahydrofuran-3-yloxy)-benzo[d] isoxazol-3-yloxymethyl]-piperi din-1 -yhnethyl]-tetrahydropyran-4-ol (PF-04995274), or a combination thereof. In some embodiments, the 5-HT4R agonist is prucalopride.

[0011] In some embodiments, the 5-HT4R agonist is administered once, twice, three times, four times, five times, six times, or seven times a week. The NMDAR antagonist can be administered once, twice, three times, four times, five times, six times, or seven times a week. In some embodiments, the 5-HT4R agonist is administered at a concentration ranging from about 0.01 mg / kg to about 40 mg / kg of body weight of the subject, optionally, from about 0.01 mg / kg to about 2 mg / kg of body weight of the subject. The NMDAR antagonist can be administered at a concentration ranging from about 0.01 mg / kg to about 40 mg / kg of body weight of the subject, optionally, from about 0.5 mg / kg to about 5 mg / kg of body weight of the subject. The administration can be oral administration, intravenous administration, intranasal administration or an administration via an injection to the subject. In some embodiments, the administration to the subject is intranasal. In some embodiments, (1) the serotonin 4 receptor (5-HT4R) agonist or the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and (2) the N-methyl-D-aspartate receptor (NMDAR) antagonist, the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof are administered sequentially or concurrently. In some embodiments, (1) the serotonin 4 receptor (5-HT4R) agonist or the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and (2) the N-methyl-D-aspartate receptor (NMDAR) antagonist, the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof are administrated in a single composition or in two separate compositions.

[0012] The administration to the subject can be performed prior to a stressor and / orafter a stressor. In some embodiments, the administration to the subject is performed about 48 hours to about 3 weeks prior to a stressor, about 72 hours to about 2 weeks prior to a stressor, or about 1 week prior to a stressor. In some embodiments, the administration to the subject is performed about 48 hours to about 3 weeks after a stressor, about 72 hours to about 2 weeks, or about 1 hour to about 1 day after a stressor. The administration to the subject can be performed at least once prior to a stressor and / or at least once after a stressor. The administration to the subject can be performed at least once before a stressor and then after a stressor.

[0013] In some embodiments, the subject had been or is diagnosed as having a stress-induced affective disorder or stress-induced psychopathology. The stress-induced affective disorder can be post-traumatic stress disorder (PTSD) or major depressive disorder (MDD). In some embodiments, the stress-induced affective disorder is selected from the group consisting of: depressive-like behavior and associated affective disorders; anhedonic behavior and associated affective disorders; anxiety and associated affective disorders; cognitive impairments and deficits and associated disorders; stress-induced fear; and combinations thereof. The stress-induced affective disorder may comprise depressive-like behavior. In some embodiments, the subject has recovered from the stress-induced affective disorder or stress-induced psychopathology and is considered at risk of relapse. The subject can be in remission from the stress-induced affective disorder or stress-induced psychopathology. In some embodiments, the subject has been treated with the 5-HT4R agonist alone, with the NMD AR antagonist alone, or with a combination of the 5-HT4R agonist and the NMD AR antagonist prior to the remission.

[0014] In some embodiments, the subject is in remission phase. In some embodiments, the subject was in response to a therapy conducted prior to the remission phase. The response can be complete response or partial response. The therapy conducted prior to the remission phase can comprise the 5-HT4R agonist alone, the NMD AR antagonist alone, or a combination of the 5-HT4R agonist and the NMD AR antagonist.

[0015] In some embodiments, the methods disclosed herein can prevent the relapse of a depressive episode even after discontinuing administration. In some embodiments, the administration does not affect the weight of the subject. The subject can be mammal, such as a human, either female or male.

[0016] The methods disclosed herein can further comprise administering an effective amount of an anti-depressant, an anxiolytic, or combinations thereof. The methods can further comprise administering an effective amount of a selective serotonin reuptake inhibitor (SSRI), or a pharmaceutically acceptable salt or derivative thereof. In some embodiments, the method can further comprise administering an effective amount of fluoxetine, paroxetine, sertraline, lithium, riluzole, prazosin, lamotrigine, ifenprodil, or combinations thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIGS. 1A-1F depict results from exemplary embodiments showing chronic injection of combined (A,5)-ketamine + prucal opride exerts antidepressant effects in male mice.FIG. 1A depicts a schematic design showing behavioral protocol and drug administration schedule. Male 129S6 / SvEv mice were exposed to 3-shock CFC stress and subsequently administered chronic i.p. injection of saline, (A,S)-ketamine, prucalopride, or combined (R,S)-ketamine + prucalopride for 2 weeks. Mice were subsequently tested in CFC re-exposure, FST, and MB. FIG. IB is a plot depicting CFC training freezing percentage for different treatment groups. During CFC training, all groups froze comparably. FIG. 1C is a plot depicting CFC reexposure freezing percentage for different treatment groups. During CFC re-exposure, (R,S)-ketamine + prucalopride (10 + 1.5 mg / kg) 2X + 7X / week significantly reduced freezing compared to saline. FIGS. 1D-1E are plots depicting FST Day 1 (FIG. ID) and Day 2 (FIG. IE) mobility time in seconds, respectively. (A,5)-ketamine (30 mg / kg) 2X / week and (A,5)-ketamine + prucalopride (10 + 1.5 mg / kg) 2X + 7X / week significantly reduced immobility time during Day 2, but not Day 1 of the FST. (A,5)-ketamine + prucalopride (10 + 1.5 mg / kg) 2X + 7X / week also significantly reduced immobility in comparison to (A,5)-ketamine (10 mg / kg), 2X / week on FST Day 2. FIG. IF is a plot showing the percentage of change in weight for different treatment groups. Mice administered (A,5)-ketamine (30 mg / kg) IX / week gained a significant amount of weight compared to saline controls, (n = 6-12 male mice per group). Error bars represent + SEM. * p < 0.05. ** < 0.01. Figures display only relevant significant comparisons; complete statistical analyses is not shown. CFC, contextual fear conditioning; i.p., intraperitoneal; RE, CFC reexposure; FST, forced swim test; Sal, saline; K, ( / ?, >)-!< etamine; P, prucalopride; K + P, (R, S - ketamine + prucalopride; mg, milligrams; kg, kilogram; X, times; sec, seconds; min, minutes.

[0018] FIGS. 2A-2F depict results from exemplary embodiments showing combined intranasal (R,S)-ketamine + prucalopride administration decreases fear expression and behavioral despair in male mice. FIG. 2A depicts a schematic of the experimental design. FIGS. 2B-2C are plots showing CFC training freezing percentage (FIG. 2B) and CFC re-exposure freezing percentage (FIG. 2C) for different treatment groups. Freezing during CFC training and reexposure was comparable across all drug groups. FIGS. 2D-2E are plots showing FST Day 1 immobility time (FIG. 2D) and FST Day 2 immobility time (FIG. 2E) in seconds, respectively. Immobility time was comparable between all groups of day 1 of the FST. P (0.75 mg / kg), 7X and K+P (10 + 1.5 mg / kg), 2X + 7X / week decreased immobility time on day 2 of the FST. FIG. 2F is a plot showing the percentage of change in weight during drug administration, (n = 6-7 male mice per group). Error bars represent + SEM. * p < 0.05. Figures display only relevant significant comparisons; complete statistical analyses is not shown. Sal, saline; K, (A,5)-ketamine; P,prucal opride; K + P, ( / ?,A')-ketamine + prucal opride; mg, milligram; kg, kilogram; CFC, contextual fear conditioning; RE, re-exposure; FST, forced swim test; sec, seconds.

[0019] FIGS. 3A-3J depict results from exemplary embodiments showing chronic injection of combined (R,S)-ketamine + prucal opride reduces behavioral despair in male mice after SEFL exposure. FIG. 3A depicts a schematic design of behavioral protocol and drug administration schedule. FIGS. 3B-3C are plots showing Ctxt C training freezing (FIG. 3B) and re-exposure freezing (FIG. 3C) percentage for different treatment groups. Freezing was comparable between all drug groups during Training and Re-exposure in Ctxt C. Freezing was significantly increased in mice administered footshock stress in comparison to Sal-administered mice given context exposure during Ctxt A re-exposure. FIG. 3D is a plot showing Ctxt A reexposure 2 freezing percentage. (K (10 mg / kg, IX) and K (30 mg / kg, 2X), significantly increased freezing compared to stressed Sal controls during Ctxt A Re-exposure 2. FIGS. 3E-3G are plots showing results from Ctxt B re-exposure. FIG.3E shows mean retrieval discrimination. FIG. 3F shows the percentage of CS+ Freezing. FIG. 3G shows the percentage of ITI Freezing. During Ctxt B Re-exposure, mean discrimination was comparable across all groups. FIGS. 3H-3I are plots showing FST Dayl (FIG. 3H) and Day 2 (FIG. 31) immobility time in seconds. On FST 2, but not FST 1, mice administered combined K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) exhibited significantly reduced immobility time when compared to stressed Sal controls. FIG.3J is a plot showing marbles buried percentage for different treatment groups. Mice administered K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) exhibited a trending reduction in marbles buried during the MB assay in comparison so stressed saline controls. FIG. 3K is a plot showing the percentage of change in weight. Change in weight was comparable across all groups, (n = 9-10 male mice per group). Error bars represent + SEM. * p < 0.05. *** p < 0.001. Figures display only relevant significant comparisons. Ctxt, context; i.p., intraperitoneal; FST, forced swim test; MB, marble burying; EPM, elevated plus maze; OFT, open field test; Sal, saline; K, (7?,5)-ketamine; P, prucalopride; K + P, ( / ?,A')-ketamine + prucalopride; mg, milligrams; kg, kilogram; X, times; CS, conditioned stimulus; sec, seconds.

[0020] FIGS. 4A-4K depict results from exemplary embodiments showing chronic injection of combined (R,S)-ketamine and prucalopride reduces behavioral despair in female mice after SEFL exposure. FIG. 4A depicts a schematic design of behavioral protocol and drug administration schedule. FIGS. 4B-4C are plots showing Ctxt C training freezing (FIG. 4B) and re-exposure freezing (FIG. 4C) percentage for different treatment groups. Freezing was significantly increased in mice administered footshock stress in comparison to saline-administered mice given context exposure. Freezing during Ctxt C Training and Re-exposure was comparable between all groups. FIG. 4D is a plot showing Ctxt A re-exposure 2 freezing percentage fordifferent treatment groups. Stressed mice administered K (10 mg / kg, IX) froze significantly more than nonstressed Sal-administered mice during Ctxt A Re-exposure 2. FIG. 4E is a plot showing mean retrieval discrimination in Context B Re-exposure for different treatment groups. Mean retrieval discrimination in Context B Re-exposure was comparable across all stress and drug groups. FIGS. 4F-4G are plots showing results from Ctxt B Re-exposure. FIG. 4F shows the percentage of CS+ Freezing. FIG. 4G shows the percentage of ITI Freezing. During Ctxt B Reexposure, all groups froze comparably. FIGS.4H-4I are plots showing FST Day 1 (FIG.4H) and Day 2 (FIG. 41) immobility time in seconds. On FST 2, but not FST 1, mice administered combined K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) exhibited significantly reduced immobility time when compared to stressed Sal controls. FIG.4J is a plot showing marbles buried percentage for different treatment groups. Marbles buried during the MB assay was comparable between all groups. FIG. 4K is a plot showing percentage of change in weight for different treatment groups. Change in weight was comparable across all groups, (n = 9-10 female mice per group). Error bars represent + SEM. * p < 0.05. *** p < 0.001. Figures display only relevant significant comparisons. Ctxt, context; i.p., intraperitoneal; FST, forced swim test; MB, marble burying; EPM, elevated plus maze; OFT, open field test; Sal, saline; K, (R,5)-ketamine; P, prucalopride; K + P, (A,5)-ketamine + prucalopride; mg, milligrams; kg, kilogram; X, times; CS, conditioned stimulus; sec, seconds.

[0021] FIGS. 5A-5G depict results from exemplary embodiments showing chronic injection of combined (R,5)-ketamine and prucalopride reduces perseverative behavior and hyponeophagia in male mice following LH stress. FIG. 5A depicts a schematic design of behavioral protocol and drug administration schedule. FIG. 5B is a plot showing escape latency in seconds for different treatment groups. There was a trending reduction in latency to escape in mice administered K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) in comparison to Sal controls.FIGS. 5C-5D are plots showing Day 1 (FIG. 5C) and Day 2 (FIG. 5D) immobility time for different treatment groups. Immobility time on days 1 and 2 of the FST was comparable across all groups. FIG. 5E is a plot showing marbles buried percentage for different treatment groups.FIGS. 5F-5G are plots depicting data from feeding experiments. FIG. 5F shows the percentage of CS+ Freezing. FIG. 5G shows the percentage of ITI Freezing. P (3 mg / kg, 7X) and K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly reduced latency to feed in the NSF when compared with Sal controls, (n = 9-10 male mice per group). Error bars represent + SEM. * p < 0.05. Figures display only relevant significant comparisons. LH, learned helplessness; i.p., intraperitoneal; FST, forced swim test; OF, open field; MB, marble burying; EPM, elevated plus maze; NSF, novelty-suppressed feeding; Sal, saline; K, (A,5)-ketamine; P, prucalopride; K + P, (A,5)-ketamine + prucalopride; mg, milligram; kg, kilogram; sec, seconds; min, minutes.

[0022] FIGS. 6A-6G depict results from exemplary embodiments showing chronic injection of combined (R,S)-ketamine and prucal opride reduces behavioral despair in female mice following LH stress. FIG. 6A depicts a schematic design of behavioral protocol and drug administration schedule. FIGS. 6B-6C are plots showing escape latency in LH testing (FIG. 6B) and FST Day 1 immobility time (FIG. 6C), respectively. Behavior during LH testing and FST 1 was comparable across all drug groups. FIG. 6D is a plot showing FST Day 2 immobility time. On FST day 2, K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly reduced immobility when compared with Sal controls. FIG.6E is a plot showing marbles buried for different treatment groups. Drug administration did not significantly alter behavior during the MB task. FIGS. 6F-6G are plots depicting data from feeding experiments. FIG. 6F shows the percentage of mice not eating. FIG. 6G shows the latency to feed. There was a trending decrease in latency to feed in the OF during the NSF in mice administered K (30 mg / kg, 2X). Latency to feed was comparable in all other groups, (n = 5 female mice per group). Error bars represent + SEM. * p < 0.05; ** p < 0.01. Figures display only relevant significant comparisons. LH, learned helplessness; i.p., intraperitoneal; FST, forced swim test; OF, open field; MB, marble burying; EPM, elevated plus maze; NSF, novelty-suppressed feeding; Sal, saline; K, (7?,5)-ketamine; P, prucal opride; K + P, ( / CS')-ketamine + prucalopride; mg, milligram; kg, kilogram; sec, seconds; min, minutes.

[0023] FIGS. 7A-7M depict results from exemplary embodiments showing combined ( / LS')-ketamine and prucalopride reduces stress-induced reductions in grooming and prevents relapse in a chronic CORT model of stress. FIG. 7A depicts a schematic design of behavioral protocol and CORT / drug administration schedule. Male mice were given 2 weeks of chronic CORT administered via drinking water (induction phase) and subsequently given 2 weeks of CORT + drug administration (treatment phase). Mice were taken off of CORT and chronic drug administration (remission phase) for 2 weeks. Then, mice were placed back on CORT (relapse phase). Behavior was assayed during treatment, remission, and relapse phases using the SST, MB, and NSF to quantify motivation, perseverative, and hyponeophagia behavior, respectively. FIG.7B is a plot showing the number of grooming bouts for different treatment groups during the initial treatment phase. During the initial treatment phase, CORT administration significantly reduced grooming in comparison to Veh controls. This reduction in grooming was rescued by administration of combined K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively), but no other drug.FIG. 7C is a plot showing marbles buried for different treatment groups during the initial treatment phase. Marble burying was comparable across all treatment and drug groups. FIGS.7D-7E are plots depicting data from feeding experiments during the initial treatment phase. FIG. 7D shows the percentage of mice not eating. FIG. 7E shows the latency to feed. Mice administered CORT + P (3 mg / kg, 7X) exhibited significantly reduced latency to feed in the NSF whencompared with CORT + Sal-administered mice. There were no other significant changes in all other Veh / CORT and drug groups. FIG. 7F is a plot showing the number of grooming bouts for different treatments groups during the remission phase. During the remission phase, in Sal controls, CORT administration significantly reduced grooming in comparison to Veh administration. Combined K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) restored grooming to levels comparable to the Veh + Sal control group. FIG. 7G is plot showing marbles buried for different treatment groups during the remission phase. Marble burying was not significantly altered by CORT or drug administration. FIGS. 7H-7I are plots depicting data from feeding experiments during the remission phase. FIG. 7H shows the percentage of mice not eating. FIG.71 shows the latency to feed. There was a trending increase in latency to feed in mice given CORT + Sal in comparison to Veh + saline. When compared with CORT + Sal controls, K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly reduced latency to feed. FIG. 7J is a plot showing the number of grooming bouts for different treatments groups during the relapse phase. In the relapse phase, in mice administered Sal, CORT significantly reduced grooming in comparison to vehicle controls. K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) administration prevented this reduction in grooming. FIG. 7K is a plot showing marbles buried for different treatment groups during the relapse phase. Marble burying was once again comparable across all CORT and drug groups. FIGS.7L-7M are plots depicting data from feeding experiments during the relapse phase.FIG. 7L shows the percentage of mice not eating. FIG. 7M shows the latency to feed. CORT + Sal-administered mice exhibited increased latency to feed in comparison to Veh + Sal mice. P (3 mg / kg, 7X) and K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly reduced latency to feed, comparable to Veh + Sal controls, (n = 9-10 male mice per group). Error bars represent + SEM. ** p < 0.01; *** p < 0.001; **** p < 0.0001. Figures display only relevant significant comparisons. CORT, corticosterone; SST, sucrose splash test; MB, marble burying; NSF, novelty-suppressed feeding; Sal, saline; K, ( / CS')-ketamine; P, prucal opride; K + P, ( / CS')-ketamine + prucalopride; no., number; mg, milligram; kg, kilogram; Veh, vehicle; sec, seconds; OF, open field.

[0024] FIGS. 8A-8F depict results from exemplary embodiments showing chronic (7?,5)-ketamine and prucalopride reduces behavioral despair in female mice. FIG. 8A depicts a schematic design of behavioral protocol and drug administration schedule. Female 129S6 / SvEv female mice were exposed to 3-shock CFC stress and then administered chronic i.p. injection of saline, (7?,5)-ketamine, prucalopride, or combined (7?,5)-ketamine + prucalopride for 2 weeks. Mice were subsequently tested in CFC re-exposure and the FST. FIG. 8B is a plot showing CFC training freezing percentage for different treatment groups. Behavior was comparable across all drug groups during CFC training. FIG. 8C is a plot showing CFC Re-exposure freezingpercentage for different treatment groups. Behavior was comparable across all drug groups during CFC re-exposure. FIGS. 8D-8E are plots showing FST Day 1 (FIG. 8D) and Day 2 (FIG. 8E) immobility time for different treatment groups. During day 2 of the FST, but not on day 1, prucalopride (0.75 mg / kg, 7X / week) and (7?,5)-ketamine + prucalopride (10, 2X + 1.5 mg / kg, 7X / week, respectively) significantly reduced immobility time compared to saline controls. FIG.8F is a plot showing the percentage of change in weight for different treatment groups. Mice administered (R,5)-ketamine (10 mg / kg, IX / week) lost a significant amount of weight when compared to mice administered saline, (n = 5-10 female mice per group). Error bars represent + SEM. * p < 0.05. **** p < 0.0001. Figures display only relevant significant comparisons. CFC, contextual fear conditioning; i.p., intraperitoneal; RE, CFC re-exposure; FST, forced swim test; Sal, saline; K, (7?,X)-ketamine; P, prucalopride; K + P, (7?,5)-ketamine + prucalopride; mg, milligrams; kg, kilogram; X, times; sec, seconds; min, minutes.

[0025] FIGS. 9A-9F depict results from exemplary embodiments showing chronic intranasal (R,5)-ketamine and prucalopride administration decreases behavioral despair in female mice. FIG. 9A depicts a schematic of the experimental design. FIGS. 9B-9C are plots showing CFC training freezing (FIG. 9B) and Re-exposure freezing (FIG. 9C) percentage for different treatment groups. All groups exhibited comparable fear expression during CFC training and reexposure. FIG. 9D is a plot showing FST Day 1 immobility time for different treatment groups. All groups exhibited comparable immobility time on day 1 of the FST. FIG. 9E is a plot showing FST Day 2 immobility time for different treatment groups. (7?,5)-ketamine + prucalopride (10 mg / kg, 2X / week + 0.75 mg / kg, 7X / week, respectively) and (7?,5)-ketamine + prucalopride (10 mg / kg, 2X / week + 1.5 mg / kg, 7X / week, respectively) decreased immobility time on day 2 of the FST in comparison to saline. (R,5)-ketamine + prucalopride (10 mg / kg, 2X / week + 1.5 mg / kg, 7X / week, respectively) also decreased immobility time when compared with (R,5)-ketamine (10 mg / kg, 2X / week) and prucalopride (1.5 mg / kg, 7X / week). FIG. 9F is a plot showing the percentage of change in weight for different treatment groups. Change in weight (%) during drug administration, (n = 5-12 female mice per group). Error bars represent + SEM. * p < 0.05. **** p < 0.0001. Sal, saline; K, (7?,X)-ketamine; P, prucalopride; K + P, (7?,5)-ketamine + prucalopride; mg, milligram; kg, kilogram; CFC, contextual fear conditioning; RE, re-exposure; FST, forced swim test; g, grams; min, minutes; sec, seconds.

[0026] FIGS. 10A-10K depict results from exemplary embodiments showing chronic intranasal (R,5)-ketamine and prucalopride administration decreases stress-enhanced fear in male mice following SEFL stress. FIG. 10A depicts a schematic of the experimental design. FIGS.10B-10D are plots depicting data from Ctxt C Training (FIG. 10B), Ctxt C Re-exposure (FIG.10C), and Ctxt A Re-exposure 2 (FIG. 10D). Behavior was comparable across all groups duringCtxt C Training, Ctxt C Re-exposure, and Ctxt A Re-exposure 2. FIG. 10E is a plot showing the mean retrieval discrimination score for different treatment groups. The mean retrieval discrimination score in Ctxt B Re-exposure was comparable across all groups. FIG. 10F is a plot showing data from Ctxt B Re-exposure. In Ctxt B Re-exposure, all groups exhibited comparable freezing during CS+ epochs. During Ctxt B Re-exposure ITI epochs, mice administered K+P (10 + 3 mg / kg) 2X + 7X / week froze significantly less than saline controls. There was also a trending but not significant decrease in freezing in mice administered K (10 mg / kg) IX / week when compared to controls. FIGS. 10H-10I are plots showing FST Day 1 (FIG. 10H) and Day 2 (FIG.101) immobility time for different treatment groups. Immobility time on days 1 and 2 of the FST was comparable across all groups. FIG. 10J is a plot showing marbles buried for different treatment groups. All groups buried a comparable number of marbles in the MB assay. FIG. 10K is a plot showing the percentage of change in weight for different treatment groups. Weight (g) during drug administration, (n = 5 male mice per group). Error bars represent + SEM. * p < 0.05. Ctxt, context; FST, forced swim test; MB, marble burying; EPM, elevated plus maze; OFT, open field test; Sal, saline; K, (R,5)-ketamine; P, prucalopride; K + P, (R,5)-ketamine + prucalopride; mg, milligram; kg, kilogram; sec, seconds.

[0027] FIG. 11 depicts results from exemplary embodiments showing combined intranasal (R,5)-ketamine and prucalopride administration decreases behavioral despair in female mice following SEFL stress. Panel A: Experimental design. Panels B-G: Freezing was comparable across all groups during SEFL, including: Ctxt C training (Panel B), Ctxt C reexposure (Panel C), Ctxt A training (Panel D), mean retrieval discrimination (Panel E), Ctxt B re-exposure CS+ freezing (Panel F), and Ctxt B re-exposure ITI freezing (Panel G). Panel H:Immobility time on day 1 of the FST was comparable across all groups. Panel I: K (10 mg / kg) IX and 2X / week, P (0.75 mg / kg) 7X / week, P (1.5 mg / kg) 7X / week, K + P (10 + 0.75 mg / kg) and (10+ 1.5 mg / kg) 2X + 7X / week significantly reduced immobility time on day 2 of the FST. Panel J: All groups buried a comparable number of marbles in the MB assay. Panel K: Change in weight (g) during drug administration, (n = 5 female mice per group). Error bars represent + SEM. * p < 0.05. ** p < 0.01. *** p < 0.001. Ctxt, context; FST, forced swim test; MB, marble burying; EPM, elevated plus maze; OFT, open field test; Sal, saline; K, (A,S)-ketamine; P, prucalopride; K + P, (A,5)-ketamine + prucalopride; mg, milligram; kg, kilogram; sec, seconds.

[0028] FIG. 12 depicts results from exemplary embodiments showing chronic prucalopride administration increases GFAP expression in dorsal CAI. Panel A: Representative image of GFAP immunostaining. Inset reveals close-up of hippocampal GFAP expression. Quantification of GFAP expression in Panel B dorsal DG, Panel C dorsal CA3, Panel D dorsal CAI, Panel E ventral DG, Panel F ventral CA3, and Panel G ventral CAI. In dorsal CAI,prucalopride (3 mg / kg, 7X / week) increased GFAP expression in comparison to all other drug groups, (n = 4-5 male mice per group). Error bars represent + SEM. ** p < 0.01. pm, micrometers; GFAP, glial fibrillary acidic protein; Sal, saline; K, ( ?,5 -ketamine; P, prucalopride; K + P, (R, S - ketamine + prucalopride; mg, milligram; kg, kilogram.

[0029] FIG. 13 depicts results from exemplary embodiments showing chronic drug administration does not alter Ki67 expression. Panel A: Representative image of Ki67 immunofluorescent staining in the DG. The number of Ki67+cells was comparable across all drug groups administered via Panel B i.p. injection or Panel C intranasally. (n = 4-5 male mice per group). Error bars represent + SEM. pm, micrometers; no., number; Sal, saline; K, ( ?,5)-ketamine; P, prucalopride; K + P, ( ?,5)-ketamine + prucalopride; mg, milligram; kg, kilogram.

[0030] FIG. 14 depicts a table summarizing the behavioral results presented in the exemplary embodiments.DETAILED DESCRIPTION

[0031] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein and made part of the disclosure herein.

[0032] All patents, published patent applications, other publications, and sequences from GenBank, and other databases referred to herein are incorporated by reference in their entirety with respect to the related technology.Definitions

[0033] Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. See, e.g. Singleton et al., Dictionary of Microbiology and Molecular Biology 2nd ed., J. Wiley & Sons (New York, NY 1994); Sambrook et al., Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Press (Cold Spring Harbor, NY 1989). For purposes of the present disclosure, the following terms are defined below.

[0034] Ranges and values may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, also specificallycontemplated and considered disclosed is the range from the one particular value and / or to the other particular value unless the context specifically indicates otherwise. All of the individual values and sub-ranges of values contained within an explicitly disclosed range are also specifically contemplated and should be considered disclosed unless the context specifically indicates otherwise. The foregoing applies regardless of whether in particular cases some or all of these embodiments are explicitly disclosed. As used herein, the term “about” and the like, when used in the context of a value, generally means plus or minus 10% of the value stated. For example, about 0.5 would include 0.45 and 0.55, about 10 would include 9 to 11, about 1000 would include 900 to 1100.

[0035] As used herein, a “subject” refers to an animal that is the object of treatment, observation or experiment. “Animals” include cold- and warm-blooded vertebrates and invertebrates such as fish, shellfish, reptiles and, in particular, mammals. “Mammal” includes, without limitation, mice; rats; rabbits; guinea pigs; dogs; cats; sheep; goats; cows; horses; primates, such as monkeys, chimpanzees, and apes, and, in particular, humans.

[0036] As used herein, a “patient” refers to a subject that is being treated by a medical professional, such as a Medical Doctor (z.e., Doctor of Allopathic medicine or Doctor of Osteopathic medicine) or a Doctor of Veterinary Medicine, to attempt to cure, or at least ameliorate the effects of, a particular disease or disorder or to prevent the disease or disorder from occurring in the first place. In some embodiments, the patient is a human or an animal. In some embodiments, the patient is a mammal.

[0037] As used herein, “administration” or “administering” refers to a method of giving a dosage of a pharmaceutically active ingredient to a vertebrate.

[0038] As used herein, a “dosage” refers to the combined amount of the active ingredients. As used herein, a “unit dosage” refers to an amount of therapeutic agent administered to a patient in a single dose. As used herein, the term “daily dose” or “daily dosage” refers to a total amount of a pharmaceutical composition or a therapeutic agent that is to be taken within 24 hours.

[0039] As used herein, the term “delivery” refers to approaches, formulations, technologies, and systems for transporting a pharmaceutical composition or a therapeutic agent into the body of a patient as needed to safely achieve its desired therapeutic effect. In some embodiments, an effective amount of the composition or agent is formulated for delivery into the blood stream of a patient.

[0040] As used herein, the term “formulated” or “formulation” refers to the process in which different chemical substances, including one or more pharmaceutically active ingredients, are combined to produce a dosage form. In some embodiments, two or more pharmaceuticallyactive ingredients can be co-formulated into a single dosage form or combined dosage unit, or formulated separately and subsequently combined into a combined dosage unit. A sustained release formulation is a formulation which is designed to slowly release a therapeutic agent in the body over an extended period of time, whereas an immediate release formulation is a formulation which is designed to quickly release a therapeutic agent in the body over a shortened period of time.

[0041] As used herein, the term “pharmaceutically acceptable” indicates that the indicated material does not have properties that would cause a reasonably prudent medical practitioner to avoid administration of the material to a patient, taking into consideration the disease or conditions to be treated and the respective route of administration. For example, it is commonly required that such a material be essentially sterile.

[0042] As used herein, the term “pharmaceutically acceptable carrier” refers to pharmaceutically acceptable materials, compositions or vehicles, such as a liquid or solid filler, diluent, excipient, solvent or encapsulating material, involved in carrying or transporting any supplement or composition, or component thereof, from one organ, or portion of the body, to another organ, or portion of the body, or to deliver an agent to a diseased tissue or a tissue adjacent to the diseased tissue. Carriers or excipients can be used to produce compositions. The carriers or excipients can be chosen to facilitate administration of a drug or pro-drug. Examples of carriers include calcium carbonate, calcium phosphate, various sugars such as lactose, glucose, or sucrose, or types of starch, cellulose derivatives, gelatin, vegetable oils, polyethylene glycols and physiologically compatible solvents. Examples of physiologically compatible solvents include sterile solutions of water for injection (WFI), saline solution, and dextrose.

[0043] As used herein, the term “pharmaceutically acceptable salt” refers to any acid or base addition salt whose counter-ions are non-toxic to the patient in pharmaceutical doses of the salts. A host of pharmaceutically acceptable salts are well known in the pharmaceutical field. If pharmaceutically acceptable salts of the compounds of this disclosure are utilized in these compositions, those salts are preferably derived from inorganic or organic acids and bases. Included among such acid salts are the following: acetate, adipate, alginate, aspartate, benzoate, benzene sulfonate, bisulfate, butyrate, citrate, camphorate, camphor sulfonate, cyclopentanepropionate, digluconate, dodecyl sulfate, ethanesulfonate, fumarate, lucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate, pectinate, persulfate, 3 -phenyl -propionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, tosylate, undecanoate, hydrohalides (e.g., hydrochlorides and hydrobromides), sulphates, phosphates, nitrates, sulphamates,malonates, salicylates, methylene-bis-b-hydroxynaphthoates, gentisates, isethionates, di-p-toluoyltartrates, ethanesulphonates, cyclohexylsulphamates, quinates, and the like. Pharmaceutically acceptable base addition salts include, without limitation, those derived from alkali or alkaline earth metal bases or conventional organic bases, such as triethylamine, pyridine, piperidine, morpholine, N-methylmorpholine, ammonium salts, alkali metal salts, such as sodium and potassium salts, alkaline earth metal salts, such as calcium and magnesium salts, salts with organic bases, such as dicyclohexylamine salts, N-methyl-D-glucamine, and salts with amino acids such as arginine, lysine, and so forth.

[0044] As used herein, “therapeutically effective amount” or “pharmaceutically effective amount” refers to an amount of therapeutic agent, which has a therapeutic effect. The dosages of a pharmaceutically active ingredient which are useful in treatment when administered alone or in combination with one or more additional therapeutic agents are therapeutically effective amounts. Thus, as used herein, a therapeutically effective amount refers to an amount of therapeutic agent which produces the desired therapeutic effect as judged by clinical trial results and / or model animal studies. The therapeutically effective amount will vary depending on the compound, the disease, disorder or condition and its severity and the age, weight, etc., of the mammal to be treated. The dosage can be conveniently administered, e.g., in divided doses up to four times a day or in sustained-release form.

[0045] As used herein, the term “treat,” “treatment,” or “treating,” refers to administering a therapeutic agent or pharmaceutical composition to a subject for prophylactic and / or therapeutic purposes. The term “prophylactic treatment” refers to treating a subject who does not yet exhibit symptoms of a disease or condition, but who is susceptible to, or otherwise at risk of, a particular disease or condition, whereby the treatment reduces the likelihood that the patient will develop the disease or condition. The term “therapeutic treatment” refers to administering treatment to a subject already suffering from a disease or condition. As used herein, a “therapeutic effect” relieves, to some extent, one or more of the symptoms of a disease or disorder. For example, a therapeutic effect may be observed by a reduction of the subjective discomfort that is communicated by a subject (e.g., reduced discomfort noted in self-administered patient questionnaire).

[0046] As used herein, the term “prophylaxis,” “prevent,” “preventing,” “prevention,” and grammatical variations thereof as used herein refers the preventive treatment of a subclinical disease-state in a subject, e.g., a mammal (including a human), for reducing the probability of the occurrence of a clinical disease-state. The method can partially or completely delay or preclude the onset or recurrence of a disorder or condition and / or one or more of its attendant symptoms or barring a subject from acquiring or reacquiring a disorder or condition or reducing a subject’s riskof acquiring or requiring a disorder or condition or one or more of its attendant symptoms. The subject is selected for preventative therapy based on factors that are known to increase risk of suffering a clinical disease state compared to the general population. “Prophylaxis” therapies can be divided into (a) primary prevention and (b) secondary prevention. Primary prevention is defined as treatment in a subject that has not yet presented with a clinical disease state, whereas secondary prevention is defined as preventing a second occurrence of the same or similar clinical disease state.

[0047] As used herein, the term “inhibit,” “inhibiting,” and “inhibition” mean to decrease an activity, response, condition, disease, or other biological parameter. This can include, but is not limited to, the complete loss of activity, response, condition, or disease. Thus, the reduction can be a 10, 20, 30, 40, 50, 60, 70, 80, 90, 100%, or any amount of reduction in between as compared to native or control levels.

[0048] The present disclosure has demonstrated that combinatorial administration of a serotonin 4 receptor (5-HT4R) agonist (e.g., prucalopride) and an N-methyl-D-aspartate receptor (NMD AR) antagonist (e.g., ketamine) can be an efficacious strategy to treat a variety of stress-induced psychiatric disorders. In some embodiments, the combinatorial drug strategy can extend benefits for combating stress-induced pathophysiology and reducing a variety of stress-induced behaviors in both sexes compared to either drug alone. It is contemplated herein that this chronic treatment strategy can prove advantageous in decreasing a broad range of stress-induced psychiatric disorders.

[0049] The present disclosure also demonstrates that combinatorial administration of a 5-HT4R agonist (e.g., prucalopride) and an NMDAR antagonist (e.g., ketamine) can exert extended therapeutic benefits to prevent depression relapse. In some embodiments, administration of prucalopride and ketamine attenuate CORT-induced impairments in grooming and stress-related feeding behavior in all phases, suggesting that this combinatorial drug treatment can provide rapid antidepressant-like action and prevent the relapse of a depressive episode, even after discontinuing administration.

[0050] Disclosed herein compounds, compositions, methods and kits for preventing and treating psychiatric disorders. In some embodiments, a method of preventing a relapse of a stress-induced behavior or disorder in a subject is provided. The method can comprise administering to the subject an effective amount of (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and an effective amount of (2) an NMDAR antagonist, a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the stress-induced behavior or disorder in the subject.

[0051] Disclosed herein also includes a method of preventing a relapse of a depression or depression-like behavior or disorder in a subject. The method can comprise administering to the subject an effective amount of a composition comprising (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, and (2) an NMDAR antagonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the depression or depression-like behavior or disorder in the subject. The depression or depression-like behavior or disorder can be stress-induced or not stress-induced.Psychiatric Disorders

[0052] Provided herein include compounds and related compositions, methods and kits for treating and preventing psychiatric disorders and behaviors including, for example, depression or depression-like or stress-induced behavior or disorders. In some embodiments, the compounds and related compositions, methods and kits disclosed herein can be used to prevent a relapse of a depression or depression-like behavior or disorder or a relapse of a stress-induced behavior or disorder in a subject. In some embodiments, the stress-induced behavior comprises fear, behavioral despair, perseverative behaviors, depression or depression-like behavior, and / or anxiety-like behavior. The depression or depression-like behavior or disorder can be stress-induced. In some embodiments, the depression or depression-like behavior or disorder is not stress-induced.

[0053] The term “relapse” as used herein refers to reappearance of a behavior or a disease / disorder after an initial period of responsiveness (e.g., complete response or partial response). In some embodiments, a subject in relapse can be a subject whose disease is in progression in response to a therapy, e.g., a non-responder. A relapse in affective disorders can refer to a return of the depressive episode after remission.

[0054] In some embodiments, the methods and compositions described herein can prevent a relapse of depression or depression-like behavior or disorder. A relapse of depression occurs when a depressive episode and accompanied symptoms return after a period of remission, typically before a full recovery. Signs of a depression relapse include, for example, a depressed mood, a loss of interest in activities a person once enjoyed, anxiety, fatigue, agitation and irritability, restlessness, changes in sleep patterns, such as insomnia or excessive sleeping, changes in appetite, feelings of worthlessness and guilt, problems with concentration and memory, physical aches and pains including unexplained headaches, stomach aches, muscle pain, and suicidal thoughts or attempted suicide. In some embodiments, the methods and compositions described herein can prevent a relapse of a depressive episode. A depressive episode is a periodof time when a subject experiences a depressed mood and other symptoms of major depressive disorder. A depressive episode can be categorized as mild, moderate, or severe depending on the number and severity of symptoms.

[0055] In some embodiments, the depression or depression-like behavior or disorder is stress-induced. A stressor is a stimulus that causes stress. It can be an event or other factor that disrupts the body’s homeostasis of temperature, blood pressure, and / or other functions. In some embodiments, a stressor is a traumatic or stressful event. Because humans have sophisticated brains and thought processes, anticipating a disruption can also be a stressor. In some embodiments, a stressor is injury, trauma, combat, warfare, surgery, an accident, a criminal assault, child abuse, natural or human-caused disasters, a crash, grief, hunger, heat, cold, chemical exposure, autoimmune disease, infectious disease, viral infection, cancer, exhaustion, physical distress, neuropathy, hyperalgesia, allodynia, emotional distress, or depression. Atraumatic event can be an event or something that threatens the person’s life or the life of a close one or it could be something witnessed. A stressor can be acute or chronic.

[0056] There are numerous physiological processes that are altered in response to stress. Among these are altered cortisol, corticotrophin, catecholamine and serotonin levels. These levels return to baseline after an acute stressor is removed. These biochemical markers of stress in turn lead to ill health and psychosocial disorders. Consequently, stress plays a major role in physical and mental health. Stress can affect the onset of, or susceptibility to disease. It can also affect the progression or course of disease even when there is another underlying pathophysiology of the disease. Recovery from an existing disease can also be delayed due to stress. For example, stress is a contributing factor to high blood pressure, heart disease, headaches, colitis, irritable bowel syndrome, temporomandibular joint disorder, cancer, peptic ulcers, insomnia, skin disorders and asthma. Stress can also aggravate other conditions such as multiple sclerosis, diabetes, herpes, mental illness, substance abuse and psychiatric disorders characterized by the presence of violent or aggressive tendencies. Particularly, stress contributes to functional somatic disorders, affective disorders and major depressive disorder (MDD). These include disorders such as chronic fatigue syndrome (CFS), fibromyalgia (FMS), Gulf War Syndrome, anxiety and post-traumatic stress disorder (PTSD).

[0057] Additional examples of use of the compositions and methods described herein include administration prior to military deployment to protect service members (active combat soldiers, battlefield surgeons, etc.) and even military working dogs against stress. Potential nonmilitary use cases include, but are not limited to: police, firefighters, first responders, emergency medical technicians (EMTs), emergency room (ER) doctors, prison guards (and prisoners), humanitarian aid workers, and refugees.

[0058] Accordingly, in some embodiments, the composition described herein can be administered to a subject prior to and / or after a stressor. In some embodiments, the composition described herein is administered to a subject prior to and / or after a stressor, and again prior to a recurrence of the stressor or a different stressor.

[0059] In some embodiments, a subject can be administered the present compounds and compositions prior to or after a stressor. For example, a subject can be administered the present compounds, composition or compositions prior to a situation in which the subject (such as an early responder or military personnel) is likely to be exposed to traumatic stress, immediately after exposure to traumatic stress, and / or when the subject feels that his or her PTSD symptoms are likely to appear.

[0060] In some embodiments, the methods and compositions described herein can prevent a relapse of stress-induced behavior or disorder, including, for example, fear, behavioral despair, perseverative behaviors, depression or depression-like behavior, and / or anxiety-like behavior.

[0061] In some embodiments, the subject had been or is diagnosed as having a stress-induced affective disorder or stress-induced psychiatric disorder, and the methods, compositions and kits disclosed herein can be used to prevent a relapse of the stress-induced affective disorder or stress-induced psychiatric disorder and the accompanied behavior including, for example, stress-induced behavior and / or depression or depression-like behavior.

[0062] There are numerous disorders that are either caused by or exacerbated by stress. Stress-induced affective disorders or stress-induced psychiatric disorders can include, but are not limited to: depressive disorder, major depressive disorder, addictive disorders such as substance abuse, anorexia, bulimia, obesity, smoking addiction, and weight addiction; anxiety disorders such as agoraphobia, anxiety disorder, obsessive compulsive disorder, panic attacks, performance anxiety, phobias, and post-traumatic stress disorder (PTSD); psychiatric disorders such as stress-induced psychiatric disorders; autoimmune diseases such as allergies, arthritis, fibromyalgia, fibromatosis lupus, multiple sclerosis, rheumatoid arthritis, Sjogren’s syndrome, and vitiligo; cancer such as bone cancer, brain cancer, breast cancer, cervical cancer, colon cancer, Hodgkin’s disease, leukemia, liver cancer, lung cancer, lymphoma, multiple myeloma, ovarian cancer, pancreatic cancer, and prostate cancer; cardiovascular disorders such as arrhythmia, arteriosclerosis, Burger’s disease, essential hypertension, fibrillation, mitral valve prolapse, palpitations, peripheral vascular disease, Raynaud’s disease, stroke, tachycardia, and Wolff-Parkinson-White Syndrome; and developmental disorders such as attention deficit disorder, concentration problems, conduct disorder, dyslexia, hyperkinesis, language and speech disorders, and learning disabilities.

[0063] In some embodiments, the subject had been or is diagnosed as having anxiety disorders. The five major types of anxiety disorders are: panic disorder; obsessive-compulsive disorder; post-traumatic stress disorder; generalized anxiety disorder; and phobias (including social phobia, also called social anxiety disorder). Each anxiety disorder has its own distinct features, but they are all bound together by the common theme of excessive, irrational fear and dread. It is common for an anxiety disorder to accompany depression, eating disorders, substance abuse, or another anxiety disorder.

[0064] Panic disorder is characterized by repeated episodes of intense fear that strike often and without warning. Physical symptoms include chest pain, heart palpitations, shortness of breath, dizziness, abdominal distress, feelings of unreality, and fear of dying. Obsessive-compulsive disorder is characterized by repeated, unwanted thoughts or compulsive behaviors that seem impossible to stop or control. Generalized Anxiety Disorder is characterized by exaggerated worrisome thoughts and tension about everyday routine life events and activities, lasting at least six months, and almost always anticipating the worst even though there is little reason to expect it; accompanied by physical symptoms, such as fatigue, trembling, muscle tension, headache, or nausea. Phobias are characterized into two major types of phobias, social phobia and specific phobia. People with social phobia have an overwhelming and disabling fear of scrutiny, embarrassment, or humiliation in social situations, which leads to avoidance of many potentially pleasurable and meaningful activities. People with specific phobia experience extreme, disabling, and irrational fear of something that poses little or no actual danger; the fear leads to avoidance of objects or situations and can cause people to limit their lives unnecessarily.

[0065] In some embodiments, the subject had been or is diagnosed as having PTSD. Typically, a subject suffering from PTSD was exposed to a traumatic event in which the person experienced, witnessed, or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others and the person’s response involved intense fear, helplessness, or horror. Having repeated intrusive memories of the trauma exposure is one of the core symptoms of PTSD. Patients with PTSD are known to display impairments in learning and memory during neuropsychological testing. Other core symptoms of PTSD include heightened stress sensitivity (startle), tension and anxiety, memory disturbances, and dissociation. PTSD can be accompanied by depression, substance abuse, or one or more other anxiety disorders. In severe cases, the person may have trouble working or socializing.

[0066] In some embodiments, the compositions and methods disclosed herein can prevent a relapse of PTSD in a subject. In some embodiments, a subject is administered the present compounds or compositions prior to a situation in which the subject (such as an early responderor military personnel) is likely to be exposed to traumatic stress, immediately after exposure to traumatic stress, and / or when the subject feels that his or her PTSD symptoms are likely to appear or reappear.

[0067] Typically, the traumatic event is persistently re-experienced in one or more of the following ways: recurrent and intrusive distressing recollections of the event, including images, thoughts, or perceptions; recurrent distressing dreams of the event; acting or feeling as if the traumatic event were recurring (includes a sense of reliving the experience, illusions, hallucinations, and dissociative flashback episodes, including those that occur on awakening or when intoxicated); intense psychological distress at exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event; and physiological reactivity on exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event. An individual suffering from PTSD also has persistent avoidance of stimuli associated with the trauma and numbing of general responsiveness (not present before the trauma), as indicated by 3 or more of the following: efforts to avoid thoughts, feelings, or conversations associated with the trauma; efforts to avoid activities, places, or people that arouse recollections of the trauma; inability to recall an important aspect of the trauma; significantly diminished interest or participation in significant activities; feeling of detachment or estrangement from others; restricted range of affect (e.g., unable to have loving feelings); sense of a foreshortened future (e.g., does not expect to have a career, marriage, children, or a normal life span); and persistent symptoms of increased arousal (not present before the trauma); or as indicated by 2 or more of the following: difficulty falling or staying asleep; irritability or outbursts of anger; difficulty concentrating; hypervigilance; and exaggerated startle response. The disturbance, which has lasted for at least a month, causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.

[0068] In some embodiments, the present compositions and methods can prevent, reduce, eliminate or delay the return of one or more of the symptoms including, but not limited to: re-experiencing of the traumatic experience in the form of intrusive memories, nightmares, or flashbacks; emotional and physical reactions triggered by reminders of the trauma; distancing from others; decreased interest in activities and other people; numbing of feelings; avoidance of trauma reminders; hyperarousal symptoms, including disrupted sleep, irritability, hypervigilance, decreased concentration; increased startle reflex; and combinations thereof.

[0069] In some embodiments, the subject had been or is diagnosed as having clinical depression, also known as major depressive disorder (MDD). Clinical depression or MDD is a serious mood disorder that can impact a person’s thoughts feeling, and behaviors. Typical symptoms include, for example, persistent sadness, tearfulness, or feelings of emptiness orhopelessness, loss of interest in activities you normally enjoy, sleep disturbances, such as insomnia or sleeping too much, unexplained physical problems, like headaches or back pain, thoughts of suicide or death, feelings of guilt or worthlessness, difficulty concentrating, thinking, or remembering things. Major depressive disorder can refer to a class of syndromes characterized by negative affect and repeated episodes of depression without any history of independent episodes of mood elevation and over-activity that fulfill the criteria of mania. The age of onset and the severity, duration and frequency of the episodes of depression are all highly variable. The disorder may begin at any age. The symptoms of major depressive disorder typically develop over days to weeks. Prodromal symptoms include generalized anxiety, panic attacks, phobias or depressive symptoms and may occur during several months preceding the episode. Individual episodes also last between 3 and 12 months but recur less frequently. Most patients are asymptomatic between episodes, but a minority of patients may develop a persistent depression, mainly in old age. Individual episodes of any severity are often precipitated by stressful life events. Common symptoms of a depressive episode include: reduced concentration and attention; reduced self-esteem and self-confidence; ideas of guilt and unworthiness, ideas or acts of self-harm or suicide; disturbed sleep; and diminished appetite. In some embodiments, a major depressive episode follows a psychosocial stressor, e.g., death of a loved one, marital separation, childbirth or the end of an important relationship. The lowered mood varies little from day to day and is often unresponsive to circumstances, yet may show a characteristic diurnal variation as the day goes on. As with manic episodes, the clinical presentation shows marked individual variations, and atypical presentations are particularly common in adolescence. In some cases, anxiety, distress, and motor agitation may be more prominent at times that the depression, and the mood change may also be masked by added features such as irritability, excessive consumption of alcohol, histrionic behavior, and exacerbation of pre-existing phobic or obsessional symptoms, or by hypochondria. In some embodiments, the MDD is treatment-resistant depression (TRD), which is a type of MDD that does not respond well to standard treatments.

[0070] In some embodiments, the subject has recovered from a stress-induced affective disorder or stress-induced psychopathology (e.g., clinical depression or PTSD) and is considered at risk of relapse. In some embodiments, the subject in need is in remission from the stress-induced affective disorder or stress-induced psychopathology (e.g., clinical depression or PTSD). The subject may have been treated with a psychotherapy prior to the remission, for example, the subject may have been treated with the 5-HT4R agonist alone, with the NMD AR antagonist alone, with a combination of the 5-HT4R agonist and the NMD AR antagonist, or other agents prior to the remission. In some embodiments, the administration of the compounds and / or composition described herein is performed to the subject in remission phase, and the subject wasresponsive (e.g., complete response or partial response) to a therapy conducted prior to the remission phase. The therapy conducted prior to the remission phase can comprise the 5-HT4R agonist alone, the NMDAR antagonist alone, or a combination of the 5-HT4R agonist and the NMD AR antagonist. In some embodiments, the therapy conducted prior to the remission phase does not comprise the 5-HT4R agonist and / or the NMDAR antagonist.Combination Treatment

[0071] Provided herein include a combination therapy of a serotonin 4 receptor (5-HT4R) agonist (e.g., prucalopride) and an N-methyl-D-aspartate (NMDAR) antagonist (e.g., ketamine) and related methods, compositions, and kits for preventing and treating depression or depression-like behavior and / or stress-induced behaviors and disorders. Disclosed herein include methods and composition to prophylactically treat a subject prior to and / or after a stressor and / or prior to the recurrence of a stressor, thereby preventing or delaying a relapse of depression or depression-like behavior and / or stress-induced behaviors and affective disorders. In some embodiments, the compositions and methods disclosed herein can prevent the relapse of a depressive episode even after the administration is discontinued (e.g., 1 day, 5 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 2 months, 3 months, 4 months or more after the discontinuation of the administration).

[0072] In some embodiments, the method of preventing a relapse of a stress-induced behavior or disorder in a subject comprise administering to the subject an effective amount of (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and an effective amount of (2) an N-methyl-D-aspartate receptor (NMDAR) antagonist, a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the stress-induced behavior or disorder in the subject. The stress-induced affective disorders can comprise depression or depressive-like behaviors.

[0073] In some embodiments, a method of preventing a relapse of a depression or depression-like behavior or disorder in a subject is disclosed. The method can comprise administering to the subject an effective amount of a composition comprising (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, and (2) an N-methyl-D-aspartate receptor (NMDAR) antagonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the depression or depression-like behavior or disorder in the subject. The depression or depressionlike behavior can be stress-induced or not stress-induced. In some embodiments, the 5- HT4R agonist is prucalopride and the NMDAR antagonist is ketamine.

[0074] The 5-HT4R agonist (e.g., prucalopride) and the NMDAR antagonist (e.g.,ketamine) can be administrated to the subject in need sequentially, separately, simultaneously. In some embodiments, the 5-HT4R agonist (e.g., prucalopride) and the NMDAR antagonist (e.g., ketamine) can be co-administered. It is to be understood that “co-administered” does not necessarily mean that the compounds and compositions are administered in a combined form (i.e., they may be administered separately, e.g., as separate compositions or formulations, or together, e.g., in the same formulation or composition) to the same or different sites at the same or different times).

[0075] The administration can be performed prior to and / or after a stressor. Alternatively or in combination, the administration can be performed prior to a recurrence of the same stressor or a different stressor. For example, the subject can be administered the compounds and / or composition described herein prior to a situation in which the subject is likely to be exposed to a stress and / or after exposure to the stress, and / or when the subject feels that his or her symptoms are likely to return.

[0076] The subject in need may have been diagnosed or is diagnosed with a stress-induced affective disorder such as depressive disorder, major depressive disorder or PTSD. In some embodiments, the subject is in a remission phase. The subject can be a mammal, such as a human. In some embodiments, the human is a female. In some embodiments, the human is a male.

[0077] In some embodiments, administering the 5-HT4R agonist (e.g., prucalopride) and the NMDAR antagonist (e.g., ketamine) synergistically prevents the relapse of depression or depression-like behavior relative to the 5-HT4R agonist (e.g., prucalopride) alone, the NMDAR antagonist (e.g., ketamine) alone, and / or the additive effect of the 5-HT4R agonist (e.g., prucalopride) alone and the NMDAR antagonist (e.g., ketamine) alone.

[0078] In some embodiments, administering the 5- HT4R agonist (e.g., prucalopride) and the NMDAR antagonist (e.g., ketamine) can enhance the subject’s resilience to stress. Resilience to stress refers to the capacity of a subject to adapt or change successfully, and / or to maintain physiological, neurological, or psychological homeostasis, in the face of a stressor (e.g., adversity). As used herein, the term “enhancing resilience” refers to increasing the ability of a subject to experience a stressor (e.g., a traumatic event) without suffering a depression or depression behavior and / or a stress-induced affective disorder, and / or with less post-event symptomatology or disruption of homeostasis and / or normal activities of daily living. In some embodiments, improving resilience can prevent a relapse of a depression or depression-like behavior and / or a stress-induced affective disorder. In some embodiments, improving resilience can reduce at least one of the signs, symptoms, or symptom clusters of a stress-induced affective disorder such as clinical depression or PTSD. In some embodiments, the present method enhances a subject’s resilience to stress, helps protect against developing stressor-related psychopathology,decrease the functional consequences of stressor-induced disorders (e.g., clinical depression, PTSD, etc.), and reduce medical morbidity and mortality.

[0079] In some embodiments, administering the 5-HT4R agonist (e.g., prucalopride) and the NMD AR antagonist (e.g., ketamine) can enhance the subject’s stress resilience by at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or a number or range between any two of these values based on the Connor-Davidson Resilience Scale. The Connor-Davidson Resilience Scale (CD-RISC) is a 25-item self-report scale, each rated on a 5-point scale (0-4), with higher scores reflecting greater resilience (Connor K M & Davidson, J R T. Development of a new resilience scale: the Connor-Davidson Resilience Scale (CD-RISC). Depression and Anxiety, 2003: 18:71-82). Resilience, psychological growth and life satisfaction can be measured with the CD-RISC, the Purpose in Life Scale, the abbreviated MOS Social Support Survey, the PTGI, and the Q-LES-Q.NMDA receptor antagonist

[0080] N-methyl-D-aspartate (NMDA) receptor antagonists are compounds antagonize, or inhibit, the action of the NMDA receptor. An NMDA receptor antagonist can be a competitive antagonist, an uncompetitive antagonist, a noncompetitive antagonist, and / or a glycine antagonist. Non-limiting examples of NMDA receptor antagonists include, but are not limited to, ketamine, dextromethorphan (DXM), histogranin, memantine, meperidine, methadone, methoxetamine (MXE), phencyclidine (PCP), nitrous oxide (N2O), AP5 (APV, R-2-amino-5-phosphonopentanoate), AP7 (2-amino-7-phosphonoheptanoic acid), CPPene ((3-[(R)-2-carboxypiperazin-4-yl]-prop-2-enyl-l-phosphonic acid), Selfotel, Amantadine, Atomoxetine, AZD6765, Agmatine, chloroform, dextrallorphan, dextromethorphan, dextrorphan, diphenidine, dizocilpine (MK-801), ethanol, eticyclidine, gacyclidine, ibogaine, magnesium, memantine, nitromemantine, rolicyclidine, tenocyclidine, methoxydine, tiletamine, neramexane, eliprodil, dexoxadrol, etoxadrol, remacemide, delucemine, WMS-2539, NEFA, 8A-PDHQ, HU-211, Aptiganel (Cerestat, CNS-1102), rhynchophylline, kynurenic acid, Rapastinel (GLYX-13), NRX-1074, 7-Chlorokynurenic acid, 4-Chlorokynurenine (AV-101), TK-40, 1- Aminocyclopropanecarboxylic acid (ACPC), L-Phenylalanine, Xenon, or analogs or derivatives thereof. Ketamine derivatives such as Rapastinel or Glyx-13 are also included. Rapastinel is an NMDA receptor glycine site partial agonist. It is an amidated tetrapeptide (Thr — Pro — Pro — Thr — NH2) which rapidly crosses the blood brain barrier, but is not active orally.

[0081] In some embodiments, compounds that are mechanistically similar to ketamine are expected to be protective against stress-induced de novo psychopathology. Such compounds include, for example, Ro 25-6981, a GluN2B-selective antagonist, which has been shown to have rapid antidepressant actions in rodent models of depression; CP- 101,606, a GluN2B-selectiveantagonist: A placebo-controlled trial of the NR2B specific NMDA antagonist CP-101, 606 plus paroxetine for treatment resistant depression (TRD); GLYX-13, a novel N-methyl-D-aspartate receptor (NMDAR) glycine-site functional partial agonist and rapid-acting antidepressant. GLYX-13 received Breakthrough Therapy designation from the U.S. Food and Drug Administration (FDA) for adjunctive treatment of MDD in January, 2016; and CX546 (Tocris), an ampakine (an AMPA receptor agonist), which relieves the respiratory depression induced by fentanyl. Non-limiting examples of the NMDA receptor antagonists also include anti-receptor antibodies, and anti-ligand antibodies. Exemplary NMDA receptor-antagonists also include several synthetic opioids that function as NMDA receptor antagonists, such as pethidine, methadone, meperidine, dextropropoxyphene, tramadol, levorphanol, and ketobemidone.

[0082] In some embodiments, the NMDA receptor antagonist is ketamine. Ketamine ((RS)-2-(2-chlorophenyl)-2-(methylamino) cyclohexanone) is an antagonist of the glutamate NMDA receptor (NMDAR). Ketamine also acts on opioid receptors, sigma receptors, muscarinic receptors, and monoamine transporters. Ketamine is a chiral compound.

[0083] As used herein, the term “ketamine” may refer to (S)-ketamine (also referred to as S(+)-ketamine or esketamine), (R)-ketamine (R(-)-ketamine), or a racemic mixture of (S)-ketamine and (R)-ketamine. In some embodiments, the ketamine compositions contain different proportions of the S(+) and R(-) stereoisomers. In some embodiments, the ketamine compositions contain only (S)-ketamine or (R)-ketamine or are enantiomerically enriched for a ketamine enantiomer. In some embodiments, the ketamine composition is enriched to contain, for example, greater than 60%, greater than 70%, greater than 80%, greater than 90%, greater than 95%, greater than 99%, or greater than 99.9 of (S)-ketamine or (R)-ketamine. See Paul et al., 2009; Paskalis et al., 2010; Noppers et al., 2011; Matthews et al., 2012 and International Patent Publication No. WO2013 / 138322.

[0084] Ketamine is a derivative of arylcyclohexylamine and contains a chiral center. Since the 1950s, a large number of arylcyclohexylamines have been synthesized: these compounds have shown a wide range of possible pharmacological activities. When administered orally, it undergoes first-pass metabolism, where it is stereo selectively metabolized into a broad array of metabolites, including norketamine, hydroxyketamines, dehydronorketamine and hydroxynorketamine (HNK). Following ketamine administration, (2S,6S;2R,6R)-HNK are the two major HNK metabolites found in the plasma and brain. Interestingly, a study has shown that the (2R,6R)-HNK metabolite is: 1) essential for the antidepressant effects of ketamine; 2) dependent on a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor activation; and 3) non-hypnotic (Zanos et al., 2016). All of these compounds are expected to behave similarly in the presently described methods, including enantiomers and non-psychotomimetic metabolites of ketamine.

[0085] In some embodiments, a NMDA receptor antagonist is a ketamine analog or a ketamine derivative. A ketamine analog or derivative can encompass ketamine’s enantiomers and non-psychotomimetic metabolites, including, for example, (2R,6R)-HNK, a metabolite of ketamine that may mediate the antidepressant effects of ketamine and lacks the ketamine-related side effects (Zanos et al., 2016); (2S,6S)-HNK, a metabolite of ketamine. Synthesis of these compounds (2R,6R)-HNK and(2S,6S)-HNK are described in Zanos et al., 2016 and WO 2013 / 056229. The use of (2R,6R)-hydroxynorketamine, (S)-dehydronorketamine and other stereoisomeric dehydro and hydroxylated metabolites of (R,S)-ketamine in the treatment of depression and neuropathic pain); (R)-ketamine, the R-enantiomer of ketamine, which has rapidonset and sustained antidepressant effects without psychotomimetic side effects (Yang et al., 2015); and (S)-ketamine, the S-enantiomer of ketamine, which is being developed as an intranasal spray, currently in phase III clinical trials for treatment-resistant depression. Additional ketamine analogs include Fluorodeschloroketamine, an analog of ketamine where the chlorine (Cl) group has been replaced by fluorine (F); and Tiletamine, an analog of ketamine commonly used as a veterinary anesthetic.5-HT4R Activators or Agonists

[0086] The serotonin 4 receptor (5-HT4R) is a G-protein coupled receptor (GPCR) that activates G protein Gs and stimulates the cAMP / PKA signaling pathway, resulting in the phosphorylation of cAMP response element binding protein (CREB) and as a consequence the expression of a number of genes involved in neuroplasticity (Vidal et al., 2014). The terms “serotonin,” “5-hydroxytryptamine” and “5-HT” refers to a phenolic amine neurotransmitter produced from tryptophan by hydroxylation and decarboxylation in serotonergic neurons of the central nervous system and enterochromaffin cells of the gastrointestinal tract. Serotonin is a precursor of melatonin.

[0087] The majority of 5-HT4RS are expressed in the brain of primates and rodents specifically in the medium spiny neurons of the striatum, the ammon’s horns (Cornu Ammonis 1 (CAI) and CA3) of the hippocampus, the granule cells of the dentate gyrus and glutamatergic neurons in the cortex and amygdala (Rebholz et al., 2018). In addition, 5-HT4RS are also found in hypothalamus, ventral pallidum, olfactory bulbs, septal area, and substantia nigra. Mice lacking the 5-HT4R display anhedonia and a context-dependent anxiety-like behavior (Amigo et al., 2016) and various 5-HT4R agonists can exert an antidepressant and anxiolytic-like activity (Samuels et al., 2016).

[0088] In humans or rodents, the expression of the 5-HT4 is found in the limbic regions (mPFC, HPC and NAc). In addition, the basal ganglia, i.e., the caudate nucleus and the lenticularnucleus (putamen and pallidum), the black matter, and the amygdala, also express the 5-HT4 receptor. The 5-HT4 receptor is expressed at the somatodendritic level and at the level of the axon terminals of efferent spinal GABAergic neurons of the striatum, the CAI and CA3 of the hippocampus, the granular cells of the dentate gyrus, and glutamatergic neurons of the cortex, the hippocampus and the amygdala. 5-HT4 receptor is also found at the peripheral level, in particular at the cardiac level, where activation thereof exerts a positive inotropic effect, at the level of the gastro-intestinal tract where it is involved in intestinal motility, at the level of the adrenal glands where it plays a role in secretion of corticosterone, and at the level of the bladder where it causes contraction of the smooth muscles.

[0089] The 5-HT4 receptor (5-HT4R) has seven transmembrane domains. The N-terminal region faces towards the extracellular environment, whereas the C-terminal domain, coupled to a Gs protein, faces towards the cytoplasm. The activation of the 5-HT4R, e.g., by an agonist, can lead to the recruitment of the Gs protein which stimulates adenylate cyclase (AC) which is responsible for the production of cAMP. Protein kinase A (PKA), activated by the cAMP, modulates different ionic currents and in particular potassium currents, the inhibition of which results in neuronal hyperexcitability. The PKA is also capable of phosphorylating the protein binding the response element to the cAMP (CREB - cAMP response element binding protein), which results in an increase in the transcription of neurotrophic brain factor (BDNF, brain-derived neurotrophic factor), involved in cognition, mood and cell survival.

[0090] The term “agonist” can refer to a substance, an agent or a compound capable of binding to and activating one or more receptors, such as 5-HT4R. The term “agonist” can refer to a compound having the ability to initiate or enhance a biological function of a target protein (e.g., one or more receptors, such as 5-HT4R), whether by enhancing or initiating the activity or expression of the target protein. 5-HT4R agonists may be compounds that activate the action of the 5-HT4 receptor. The term “agonist” is defined in the context of the biological role of the target protein. In some embodiments, an agonist is an agent that binds to a receptor (e.g., 5-HT4R) and activates the receptor to produce a biological response. While agonists provided herein can specifically interact with (e.g., bind to) the target protein, compounds that initiate or enhance a biological activity of the target protein by interacting with other members of the signal transduction pathway of which the target protein is a member are also specifically included within this definition. A 5-HT4R agonist can be a compound or an agent that activates the action of 5-HT4R. A 5-HT4R agonist can be any agent that acts directly or indirectly through or upon 5-HT4R to produce a pharmacological effect. The terms “agonist of 5-HT4R”, “agonist of the 5-HT4 receptor”, “5-HT4 receptor agonist”, and “5-HT4R agonist” are used interchangeably herein.

[0091] The 5-HT4R agonist can be selective for 5-HT4 receptors or it can be non-selective, exhibiting agonist or antagonist activity at other serotonin receptors. In some embodiments, the 5-HT4R agonist is selective for 5-HT4 receptors.

[0092] The 5-HT4R agonists can include full agonists, partial agonists, or mixed 5-HT4R agonists / antagonists. “Full agonists” may refer to agents bind to and activate a receptor with the maximum response that an agonist can elicit at the receptor. An agent may act as a full agonist in some tissues and as a partial agonist in other tissues, depending upon the relative numbers of receptors and differences in receptor coupling. “Partial agonists” may refer to compounds able to bind and activate a given receptor, but having only partial efficacy at the receptor relative to a “full agonist” or complete agonist. Partial agonists can act as antagonists when competing with a full agonist for receptor occupancy and producing a net decrease in the receptor activation compared to the effects or activation observed with the full agonist alone. Partial agonists may refer to mixed agonists / antagonists, which differentially affect a receptor function within different dose ranges. For example, partial agonists may serve as agonists at lower doses, and as antagonists at higher doses. Partial agonists can be compounds that have reduced efficacy for inducing conformational change in receptors (typically 40-80%) relative to full agonists, and which may induce agonist effects at low dose but antagonist effects at high dose.

[0093] In some embodiments, the 5-HT4R agonist is an indole, a benzamide, a benzoate, an arylketone or a benzamide. Non-limiting examples of 5-HT4R agonists include, 1-(4-amino-5-chloro-2-methoxyphenyl)-3-[l(n-butyl)-4-piperidinyl]-l-propanone HC1 (RS-67,333 or RS67333), 4-amino-5-chloro-2,3-dihydro-N-[l-3-methoxypropyl)-4-piperidinyl]-7-benzofuran carboxamide monohydrochloride (prucal opride), 4-[4-[4-Tetrahydrofuran-3-yloxy)-benzo[d]isoxazol-3-yloxymethyl]-piperidin-l-ylmethyl]-tetrahydropyran-4-ol (PF-04995274), and combinations thereof. Non-limiting examples of 5-HT4R agonists also include, 2-[l-(4-Piperonyl)piperazinyl]benzothiazole (PPB), 5-methoxytryptamine, PRX-03140, cisapride ((±)-cis-4-amino-5-chloro-N-[l-[3-(4-fluorophenoxy)propyl]-3-methoxy-4-piperidinyl]-2-methoxybenzamide monohydrate), BIMU-8 (2,3-Dihydro-N-[(3-endo)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl]-3-(l-methylethyl)-2-oxo-lH-benzimidazole-l-carboxamide, RS67506 (methylsulphonylamino)ethyl-4-piperidinyl] -1 -propanone hydrochloride), mosapride (4-amino- 5-chloro-2-ethoxy-N-[[4-[(4-fluorophenyl)methyl]-2-morpholinyl]methyl]benzamide citrate), tegaserod (2-[(5-Methoxy-lH-indol-3-yl)methylene]-N-pentyl-hydrazinecarboximidamide maleate), ML10302 (4-Amino-5-chloro-2-methoxybenzoic acid 2-(l-piperidinyl)ethyl ester hydrochloride), velusetrag (TD-5108) (N-[(lR,3R,5S)-8-[(2R)-2-hydroxy-3-(N-methylmethanesulfonamido)propyl]-8-azabicyclo[3.2.1]octan-3-yl]-2-oxo-l-(propan-2-yl)-l,2-dihydroquinoline-3-carboxamide), naropride (ATI-7505) ([(3R)-l-azabicyclo[2.2.2]octan-3-yl] 6-[(3S,4R)-4-[(4-amino-5-chloro-2-methoxybenzoyl)amino]-3-methoxypiperidin-l-yl]hexanoate, cinitapride (4-amino-N-[l-(cyclohex-3-en-l-ylmethyl)piperidin-4-yl]-2-ethoxy-5-nitrobenzamide), metoclopramide (4-amino-5-chloro-N-(2-(diethylamino)ethyl)-2-methoxybenzamide), renzapride (ATL-1251, BRL 24924, (±)-endo-4-amino-5-chloro-2-methoxy-N-(l -azabicyclo [3.3.1]non-4-yl) benzamide), RQ-00000010 (4-{[4-({[4-(2,2,2-trifluoroethoxy)- 1 ,2-benzisoxazol-3-yl]oxy }methyl)piperidin- 1 -yl]methyl }tetrahydro-2H-pyran-4-carboxylic acid), SUVN-D4010 (l-isopropyl-3-{5-[l-(3-methoxy propyl) piperidin-4-yl]-[l,3,4]oxadiazol-2-yl}-lH-indazole), TD-8954 (4-{(4-[(2-isopropyl-lH-benzoimidazole-4-carbonyl)amino]methyl}- piperi din- l-ylmethyl)piperi dine- 1 -carboxylic acid methyl ester), SC53116 (4-Amino-5-chloro-N-[[(lS,7aS)-hexahydro-lH-pyrrolizin-l-yl]methyl]-2-methoxy-benzamide), BIMU-1 (3-ethyl-2,3-dihydro-N-(8-methyl-8-azabicyclo[3.2.1 ] oct-3 -yl)-2-oxo-lH-benzimidazole-1 -carboxamide hydrochloride), donecopride (MR31147, which is: l-(4-amino-5-chloro-2-methoxyphenyl)-3 -[ 1 -(cyclohexylmethyl)-4-piperidinyl]propan- 1 -one), LS 650155 (Caeserod, which is: 5-(8-amino-7-chloro-2,3-dihydrobenzo[b][l,4]dioxin-5-yl)-3-(l-phenethylpiperidin-4-yl)-l,3,4-oxadiazol-2(3H)-one hydrochloride), PF-00885706, N-[2- [(lR,8S)-4-[[4-(cyclobutylamino)-5-(trifluoromethyl)pyrimidin-2-yl]amino]-l 1-azatricyclo[6.2.1 ,02,7]undeca-2(7),3,5-trien-l l-yl]-2-oxoethyl]acetamide, and combinations thereof.

[0094] In some embodiments, the 5-HT4R agonist is RS-67,333. RS-67,333 is a high-affinity 5-HT4R partial agonist (Eglen et al., 1995). This drug is effective in improving behavioral deficits, decreasing the number of amyloid plaques as well as level of amyloid beta (AP) species, and decreasing hippocampal astrogliosis and microgliosis in the 5xFAD mouse model of Alzheimer’s disease (AD) (Giannoni et al., 2013). RS67333 is an arylketone. Incorporating an n-butyl group on the piperidine has increased the agonist activity with great effectiveness, optimal selectivity, and excellent bioavailability. Its increased hydrophobicity helps pass the blood-brain barrier, allowing for penetration into the brain (Eglen et al. 1995).

[0095] In some embodiments, the 5-HT4R agonist is prucalopride. Prucalopride is a selective, high affinity 5-HT4R agonist (Prins et al., 1999). Prucalopride is a derivative of the family of benzofurans which exhibits increased selectivity for 5-HT4 receptor but no affinity for the hERG (human Ether-a-go-go Related Gene) channels. In 2018, it was approved by the FDA for chronic constipation and is currently being tested for chronic intestinal pseudo-obstruction. Prucalopride has also been tested in two separate clinical trials to investigate its effects on emotional processing in health volunteers after an acute (e.g., single dose) or chronic (e.g., 1 week) administration (Morris et al., 2017; Zanos and Gould, 2018).

[0096] In some embodiments, the 5-HT4R agonist is PF-04995274 which is a potent, partial 5-HT4R agonist (Grimwood et al., 2011). A clinical trial was conducted to evaluate PF-04995274, alone or in combination with donepezil, on scopolamine-induced deficits in psychomotor and cognitive function in healthy adults. However, this trial was terminated, but not due to safety concerns. Currently, a clinical trial is underway to test whether adjunctive administration of PF-04995247 has positive effects on emotional processing and neural activity in mediated, treatment-resistant (TRD) depressed patients compared to placebo (Morris et al., 2017).

[0097] The 5-HT4R agonist can be, e.g., tegaserod which is a partial agonist of the 5-HT4R, with moderate affinity for the 5-HTi (agonist) and 5-HT2A-C (antagonist) receptors. In some embodiments, the 5-HT4R agonist is cisapride. Cisapride is a parasympathomimetic which, by activating the 5-HT4R, increases the acetylcholine liberated in the enteric nervous system. In some embodiments, the 5-HT4R agonist is cinitapride. Cinitapride is a benzamide which acts as a 5-HTIA and 5-HT4 receptor agonist, and a 5-HT2A receptor antagonist. In some embodiments, the 5-HT4R agonist is mosapride. Mosapride is a selective 5-HT4R agonist, the main active metabolite of which acts as a 5-HTs receptor antagonist. In some embodiments, the 5-HT4R agonist is metoclopramide. Metoclopramide is a 5-HT4 and 5-HTSA receptor agonist. It is a D2 receptor antagonist. It is also an Ml muscarinic receptor agonist, and an acetylcholinesterase inhibitor. In some embodiments, the 5-HT4R agonist is SUVN-D4010. SUVN-D4010 is a powerful, selective and effective 5-HT4R partial agonist, having good bioavailability via the oral route. In some embodiments, the 5-HT4R agonist is mixed 5-HTR agonists / antagonists including, but not limited to, buspirone, mianserin, trazodone, and mirtazapine.Pharmaceutical Compounds

[0098] The pharmaceutical compounds, including 5-HT4R agonists (e.g., prucalopride) and NMDAR antagonists (e.g., ketamine), used in the present methods and compositions include all hydrates, solvates, and complexes of the compounds described herein. If a chiral center or another form of an isomeric center is present in a present compound, all forms of such isomer or isomers, including enantiomers and diastereomers, are intended to be covered herein. Compounds containing a chiral center can be used as a racemic mixture, an enantiomerically enriched mixture, or the racemic mixture may be separated using well-known techniques and an individual enantiomer can be used alone. The compounds described in the present disclosure can be in racemic form or as individual enantiomers. The enantiomers can be separated using known techniques, such as those described in IUPAC (1997) Pure and Applied Chemistry 69:1469-1474. In cases in which compounds have unsaturated carbon-carbon double bonds, both the cis (Z) and trans (E) isomers are within the scope of this disclosure. In cases wherein compounds may exist in tautomeric forms, such as keto-enol tautomers, each tautomeric form is contemplated as being included within this disclosure whether existing in equilibrium orpredominantly in one form.

[0099] When the structure of the compounds used in this disclosure includes an asymmetric carbon atom such compound can occur as racemates, racemic mixtures, and isolated single enantiomers. All such isomeric forms of these compounds are expressly included in this disclosure. Each stereogenic carbon can be of the R or S configuration. It is to be understood accordingly that the isomers arising from such asymmetry (e.g., all enantiomers and diastereomers) are included within the scope of this disclosure, unless indicated otherwise. Such isomers can be obtained in substantially pure form by classical separation techniques and by stereochemically controlled synthesis, such as those described in “Enantiomers, Racemates and Resolutions” by J. Jacques, A. Collet and S. Wilen, Pub. John Wiley & Sons, NY, 1981. For example, the resolution can be carried out by preparative chromatography on a chiral column.

[0100] The present disclosure is also intended to include use of all isotopes of atoms occurring on the compounds disclosed herein. Isotopes include those atoms having the same atomic number but different mass numbers. Isotopically-labeled compounds can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described herein using appropriate isotopically-labeled reagents in place of the nonlabeled reagents employed.

[0101] The compounds of the instant disclosure can be in a salt form. As used herein, a “salt” is a salt of the instant compound which has been modified by making acid or base, salts of the compounds. In the case of compounds used for treatment of mammals, the salt is pharmaceutically acceptable. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as phenols. The salts can be made using an organic or inorganic acid. Such acid salts are chlorides, bromides, sulfates, nitrates, phosphates, sulfonates, formates, tartrates, maleates, malates, citrates, benzoates, salicylates, ascorbates, and the like. Phenolate salts are the alkaline earth metal salts, sodium, potassium or lithium. The term “pharmaceutically acceptable salt” in this respect, refers to the relatively non-toxic, inorganic and organic acid or base addition salts of compounds of the present invention. These salts can be prepared in situ during the final isolation and purification of the compounds of the invention, or by separately treating a purified compound of the invention in its free base or free acid form with a suitable organic or inorganic acid or base, and isolating the salt thus formed. Representative salts include the hydrobromide, hydrochloride, sulfate, bisulfate, phosphate, nitrate, acetate, valerate, oleate, palmitate, stearate, laurate, benzoate, lactate, phosphate, tosylate, citrate, maleate, fumarate, succinate, tartrate, napthylate, mesylate, glucoheptonate, lactobionate, and laurylsulphonate salts and the like. (See, e.g., Berge et al. (1977) “Pharmaceutical Salts”, J. Pharm. Sci. 66:1-19).

[0102] The present methods also encompass administering a physiologically functional derivative of the present compound. As used herein, the term “physiologically functional derivative” refers to a compound (e.g., a drug precursor) that is transformed in vivo to yield the present compound or its active metabolite, or a pharmaceutically acceptable salt, hydrate or solvate of the compound. The transformation may occur by various mechanisms (e.g., by metabolic or chemical processes), such as, for example, through hydrolysis in blood. Prodrugs are such derivatives, and a discussion of the use of prodrugs is provided by T. Higuchi and W. Stella, “Pro-drugs as Novel Delivery Systems,” Vol. 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987.Pharmaceutical Compositions

[0103] In some embodiments, the 5-HT4R agonists, NMDAR antagonists and pharmaceutically acceptable salt, derivative, or metabolite thereof are formulated as a pharmaceutical composition. Accordingly, the disclosure further provides a pharmaceutical composition, which comprises the present agent or compound and / or salts, solvates and physiological functional derivatives thereof, and one or more pharmaceutically acceptable carriers, diluents, or excipients. The carrier(s), diluent(s) or excipient(s) must be acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. The 5-HT4R agonists and NMDAR antagonists can be formulated as a single pharmaceutical composition or separate pharmaceutical compositions.

[0104] The term “composition”, as in pharmaceutical composition, is intended to encompass a product comprising the active ingredient(s), and the inert ingredient(s) (pharmaceutically acceptable excipients) that make up the carrier, as well as any product which results, directly or indirectly, from combination, complexation or aggregation of any two or more of the ingredients, or from dissociation of one or more of the ingredients, or from other types of reactions or interactions of one or more of the ingredients. Accordingly, the pharmaceutical compositions of the present invention encompass any composition made by admixing a compound or compounds, and pharmaceutically acceptable excipients. Acceptable excipients, diluents, and carriers for therapeutic use are well known in the pharmaceutical art, and are described, for example, in Remington: The Science and Practice of Pharmacy. Lippincott Williams & Wilkins (A. R. Gennaro edit. 2005). The choice of pharmaceutical excipient, diluent, and carrier can be selected with regard to the intended route of administration and standard pharmaceutical practice.

[0105] Pharmaceutical compositions of the present disclosure can be presented in unit dose forms containing a predetermined amount of active ingredient per unit dose. Such a unit may contain, for example, 5 pg to 1 g, preferably 1 mg to 700 mg, more preferably 5 mg to 100 mg ofthe present compound, depending on the condition being treated, the route of administration and the age, weight and condition of the patient. Such unit doses can therefore be administered more than once a day. Preferred unit dosage compositions are those containing a daily dose or sub-dose (for administration more than once a day), as herein above recited, or an appropriate fraction thereof, of an active ingredient. Furthermore, such pharmaceutical compositions can be prepared by any of the methods well known in the pharmacy art.

[0106] Pharmaceutical compositions of the disclosure can be adapted for administration by any appropriate route, for example by the oral (including buccal or sublingual), inhaled, intranasal, ocular, or parenteral (including intravenous and intramuscular) route. In some embodiments, the present composition can be injected. Such compositions can be prepared by any method known in the art of pharmacy, for example by bringing into association the active ingredient with the carrier(s) or excipient(s). Further methods of administration include mucosal, such as nasal, sublingual, vaginal, buccal, or rectal; or transdermal administration to a subject.

[0107] In some embodiments, the present disclosure provides a pharmaceutical composition adapted for administration via the intranasal route. Intranasal administration is a non-invasive method of drug delivery that can eliminate the need for intravenous injections while still achieving rapid, effective blood levels of the composition administered. In general, intranasal delivery has many advantages, including, for example, ease of administration, rapid onset of action, and avoidance of the blood-brain barrier, first-pass metabolism and systemic side effects. Specifically, the rich vascular plexus of the nasal cavity provides a direct route into the blood stream for medications that easily cross mucous membranes. This direct absorption into the blood stream avoids gastrointestinal destruction and hepatic first pass metabolism (destruction of drugs by liver enzymes) allowing more drug to be cost-effectively, rapidly, and predictably bioavailable than if it were administered orally. The rates of absorption and plasma concentrations are typically comparable to intravenous administration, and are typically better than subcutaneous or intramuscular routes. Intranasal drug administration is essentially painless, and does not require sterile technique, intravenous catheters or other invasive devices, and it is immediately and readily available for all patients. Furthermore, because the nasal mucosa is nearby the brain, cerebrospinal fluid (CSF) drug concentrations can exceed plasma concentrations. Intranasal administration can rapidly achieve therapeutic brain and spinal cord (CNS) drug concentrations.

[0108] Pharmaceutical compositions adapted for nasal and pulmonary administration can comprise solid carriers such as powders, which can be administered by rapid inhalation through the nose. Compositions for nasal administration can comprise liquid carriers, such as sprays or drops. Alternatively, inhalation directly through into the lungs can be accomplished by inhalation deeply or installation through a mouthpiece. These compositions may compriseaqueous or oil solutions of the active ingredient. Compositions for inhalation can be supplied in specially adapted devices including, but not limited to, pressurized aerosols, nebulizers or insufflators, which can be constructed so as to provide predetermined dosages of the active ingredient.

[0109] The pharmaceutical composition can be formulated as a nasal spray comprising the 5-HT4R agonist and the NMDAR antagonist individually or in combination in a volume between about 25 pL and about 1000 pL per dose. In some embodiments, the nasal spray formulation is an aqueous solution, aqueous suspensions, aqueous emulsion, non-aqueous solution, non-aqueous suspension or non-aqueous emulsion.

[0110] In some embodiments, the nasal spray pharmaceutical formulation comprises one or more absorption enhancement agents, and optionally one or more agents selected from isotonicity agents, stabilizing agents, preservatives, taste-masking agents, viscosity modifiers, antioxidants, buffers and pH adjustment agents.[OHl] In some embodiments, the nasal spray formulation comprises one or more absorption enhancers selected from dodecyl maltoside, benzalkonium chloride, oleic acid, or salt thereof, polysorbate 20, polysorbate 80, and sodium lauryl sulfate. In some embodiments, the formulation comprises one or more absorption enhancers selected from alcohol, aprotinin, benzalkonium chloride, benzyl alcohol, capric acid, ceramides, cetylpyridinium chloride, chitosan, cyclodextrins, deoxycholic acid, decanoyl, dimethyl sulfoxide, glyceryl monooleate, glycofurol, glycofurol, glycosylated sphingosines, glycyrrhetinic acids, 2-hydroxypropyl-P-cyclodextrin, laureth-9, lauric acid, lauroyl carnitine, lysophosphatidylcholine, menthol, poloxamer 407 or F68, poly-L-arginine, polyoxyethylene-9-lauryl ether, isopropyl myristate, isopropyl palmitate, lanolin, light mineral oil, linoleic acid, menthol, myristic acid, myristyl alcohol, oleic acid, or salt thereof, oleyl alcohol, palmitic acid, polysorbate 20, polysorbate 80, propylene glycol, polyoxyethylene alkyl ethers, polyoxylglycerides, pyrrolidone, quillaia saponin, salicylic acid, sodium salt, P-sitosterol P-D-glucoside, sodium lauryl sulfate, sucrose cocoate, taurocholic acid, taurodeoxycholic acid, taurodihydrofusidic acid, thymol, tricaprylin, triolein, and alkylsaccharides.

[0112] In some embodiments, the nasal spray pharmaceutical formulation comprises an isotonicity agent (e.g., dextrose, glycerin, mannitol, potassium chloride, or sodium chloride). In some embodiments, the isotonicity agent is sodium chloride.

[0113] The nasal spray formulation additionally can comprise, e.g., a stabilizing agent. In some embodiments, the stabilizing agent is ethylenediaminetetraacetic acid (EDTA) or a salt thereof. In some embodiments, the EDTA is disodium EDTA. In some embodiments, the nasal spray formulation comprises from about 0.001% (w / v) to about 1% (w / v) of disodium EDTA.

[0114] In some embodiments, the nasal spray formulation additionally comprises a preservative. In some embodiments, the preservative is benzalkonium chloride.

[0115] In some embodiments, the nasal spray formulation further comprises an antioxidant, e.g., an antioxidant selected from alpha tocopherol, arachidonic acid, ascorbic acid, ascorbyl palmitate, benzethonium chloride, benzethonium bromide, benzalkonium chloride, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), capric acid, caproic acid, carbon dioxide, cetylpyridium chloride, chelating agents, chitosan derivatives, citric acid monohydrate, dodecyl dimethyl aminopropionate, enanthic acid, erythorbic acid, ethyl oleate, fumaric acid, glycerol oleate, glyceryl monostearate, lauric acid, limonene, linolenic acid, lysine, malic acid, menthol, methionine, monothioglycerol, myristic acid, oleic acid, palmitic acid, pelargonic acid, peppermint oil, phosphoric acid, polysorbates, potassium metabisulfite, propionic acid, propyl gallate, sodium ascorbate, sodium bisulfite, sodium caprate, sodium desoxycholate, sodium deoxyglycolate, sodium formaldehyde sulfoxylate, sodium glycocholate, sodium hydroxybenzoyal amino caprylate, sodium lauryl sulfate, sodium metabisulfite, sodium sulfite, sodium taurocholate, sodium thiosulfate, stearic acid, sulfur dioxide and a combination thereof.

[0116] In some embodiments, the nasal spray formulation comprises a buffering agent. Buffering agents include, but are not limited to, adipic acid, boric acid, calcium carbonate, calcium hydroxide, calcium lactate, calcium phosphate, tribasic, citric acid monohydrate, dibasic sodium phosphate, diethanolamine, glycine, maleic acid, malic acid, methionine, monobasic sodium phosphate, monoethanolamine, monosodium glutamate, phosphoric acid, potassium citrate, sodium acetate, sodium bicarbonate, sodium borate, sodium carbonate, sodium citrate dihydrate, sodium hydroxide, sodium lactate, and triethanolamine.

[0117] In some embodiments, the nasal spray pharmaceutical formulation comprises between about 1 mg / mL and about 100 mg / mL (e.g., 1 mg / mL, 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, 50 mg / mL, 60 mg / mL, 70 mg / mL, 80 mg / mL, 90 mg / mL, 100 mg / mL, a number or range between any two of these values)per dose 5-HT4R agonists (e.g., prucalopride) and / or NMDAR antagonists (e.g., ketamine). In some embodiments, the nasal spray pharmaceutical formulation comprises between about 5 mg and about 100 mg (e.g., 5 mg, 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, or a number or range between any two of these values) per dose dispensed from the device of 5-HT4R agonists (e.g., prucalopride) and / or NMDAR antagonists (e.g., ketamine). Single, bi- or multi-dose sprays are administered as needed.

[0118] The present disclosure provides a pharmaceutical composition adapted for administration by the oral route. Pharmaceutical compositions of the present disclosure which are adapted for oral administration may be presented as discrete units such as capsules or tablets; powders or granules; solutions or suspensions in aqueous or non-aqueous liquids; edible foams orwhips; or oil-in-water liquid emulsions or water-in-oil liquid emulsions.

[0119] For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic pharmaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Powders are prepared by comminuting the compound to a suitable fine size and mixing with a similarly comminuted pharmaceutical carrier such as an edible carbohydrate, as, for example, starch or mannitol. Flavoring, preservative, dispersing and coloring agent can also be present.

[0120] Capsules are made by preparing a powder mixture, as described above, and filling formed gelatin sheaths. Glidants and lubricants such as colloidal silica, talc, magnesium stearate, calcium stearate or solid polyethylene glycol can be added to the powder mixture before the filling operation. A disintegrating or solubilizing agent such as agar-agar, calcium carbonate or sodium carbonate can also be added to improve the availability of the medicament when the capsule is ingested.

[0121] Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, com sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum and the like. Tablets are formulated, for example, by preparing a powder mixture, granulating or slugging, adding a lubricant and disintegrant and pressing into tablets. A powder mixture is prepared by mixing the compound, suitably comminuted, with a diluent or base as described above, and optionally, with a binder such as carboxymethylcellulose, an alginate, gelatin, or polyvinyl pyrrolidone, a solution retardant such as paraffin, a resorption accelerator such as a quaternary salt and / or an absorption agent such as bentonite, kaolin or dicalcium phosphate. The powder mixture can be granulated by wetting with a binder such as syrup, starch paste, acadia mucilage or solutions of cellulosic or polymeric materials and forcing through a screen. As an alternative to granulating, the powder mixture can be run through the tablet machine and the result is imperfectly formed slugs broken into granules. The granules can be lubricated to prevent sticking to the tablet forming dies by means of the addition of stearic acid, a stearate salt, talc or mineral oil. The lubricated mixture is then compressed into tablets. The compounds of the present invention can also be combined with a free-flowing inert carrier and compressed into tablets directly without going through the granulating or slugging steps. A clear or opaque protective coating consisting of a sealing coat of shellac, a coating of sugar or polymeric materialand a polish coating of wax can be provided. Dyestuffs can be added to these coatings to distinguish different unit dosages.

[0122] Oral fluids such as solution, syrups and elixirs can be prepared in dosage unit form so that a given quantity contains a predetermined amount of the compound. Syrups can be prepared by dissolving the compound in a suitably flavored aqueous solution, while elixirs are prepared through the use of a non-toxic alcoholic vehicle. Suspensions can be formulated by dispersing the compound in a non-toxic vehicle. Solubilizers and emulsifiers such as ethoxylated isostearyl alcohols and polyoxy ethylene sorbitol ethers, preservatives, flavor additive such as peppermint oil or natural sweeteners or saccharin or other artificial sweeteners, and the like can also be added.

[0123] It should be understood that, in addition to the ingredients particularly mentioned above, the compositions may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavoring agents.

[0124] In some embodiments, the pharmaceutical composition disclosed herein is administered via the intravenous route. Pharmaceutical compositions adapted for parenteral administration, including intravenous administration, include aqueous and non-aqueous sterile injectable solutions or suspensions, which may contain anti-oxidants, buffers, bacteriostats, and solutes that render the compositions substantially isotonic with the blood of the subject. Other components which can be present in such compositions include water, alcohols, polyols, glycerine, and vegetable oils. Compositions adapted for parental administration can be presented in unit-dose or multidose containers, such as sealed ampules and vials, and can be stored in a freeze-dried (lyophilized) condition requiring only the addition of a sterile carrier, immediately prior to use. Extemporaneous injection solutions and suspensions can be prepared from sterile powders, granules, and tablets. Suitable vehicles that can be used to provide parenteral dosage forms of the invention are well known to those skilled in the art. Examples include: water for injection USP; aqueous vehicles such as Sodium Chloride Injection, Ringer’s Injection, Dextrose Injection, Dextrose and Sodium Chloride Injection, and Lactated Ringer’s Injection; water-miscible vehicles such as ethyl alcohol, polyethylene glycol, and polypropylene glycol; and nonaqueous vehicles such as corn oil, cottonseed oil, peanut oil, sesame oil, ethyl oleate, isopropyl myristate, and benzyl benzoate.Dosages

[0125] In some embodiments, the effective or therapeutically effective amount or dose of the 5-HT4R agonist (e.g., prucalopride), NMD AR antagonist (e.g., ketamine) or an analog, or a pharmaceutically acceptable salt, derivative, or metabolite thereof is about 0.01 to about 40 mgper kilogram of body weight of the subject (mg / kg), i.e., from about 0.01 mg / kg to about 40 mg / kg of body weight.

[0126] In some embodiments, the effective or therapeutically effective amount or dose of the 5-HT4R agonist (e.g., prucalopride) and / or NMD AR antagonist (e.g., ketamine) is about 0.01 mg / kg, about 0.05 mg / kg, about 0.1 mg / kg, about 0.2 mg / kg, about 0.3 mg / kg, about 0.4 mg / kg, about 0.5 mg / kg, about 0.6 mg / kg, about 0.7 mg / kg, about 0.8 mg / kg, about 0.9 mg / kg, about 1.0 mg / kg, about 1.1 mg / kg, about 1.2 mg / kg, about 1.3 mg / kg, about 1.4 mg / kg, about 1.5 mg / kg, about 1.6 mg / kg, about 1.7 mg / kg, about 1.8 mg / kg, about 1.9 mg / kg, about 2.0 mg / kg, about 3.0 mg / kg body weight, about 5.0 mg / kg body weight, about 10.0 mg / kg body weight, about 15.0 mg / kg body weight, about 20.0 mg / kg body weight, about 25.0 mg / kg body weight, about 30.0 mg / kg body weight, about 35.0 mg / kg body weight, or about 40.0 mg / kg, or a number or range between any two of these values, body weight of the subject.

[0127] In some embodiments, the 5-HT4R agonist (e.g., prucalopride), an analog, or a pharmaceutically acceptable salt, derivative, or metabolite thereof is administered at a concentration ranging from about 0.01 to about 40 mg / kg of body weight. For example, the concentration can be at about 0.01 mg / kg, 0.1 mg / kg, 0.5 mg / kg, 1 mg / kg, 1.5 mg / kg, 2.0 mg / kg, 2.5 mg / kg, 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg, 9 mg / kg, 10 mg / kg, 11 mg / kg, 12 mg / kg, 13 mg / kg, 14 mg / kg, 15 mg / kg, 16 mg / kg, 17 mg / kg, 18 mg / kg, 19 mg / kg, 20 mg / kg, 21 mg / kg, 22 mg / kg, 23 mg / kg, 24 mg / kg, 25 mg / kg, 26 mg / kg, 27 mg / kg, 28 mg / kg, 29 mg / kg, 30 mg / kg, 31 mg / kg, 32 mg / kg, 33 mg / kg, 34 mg / kg, 35 mg / kg, 36 mg / kg, 37 mg / kg, 38 mg / kg, 39 mg / kg, 40 mg / kg, or a number or range between any two of these values, of body weight of the subject. In some embodiments, the 5-HT4R agonist is administered at a concentration ranging from about 0.5 mg / kg to about 5 mg / kg, optionally from about 1 mg / kg to about 5 mg / kg.

[0128] In some embodiments, the 5-HT4R agonist (e.g., prucalopride), an analog, or a pharmaceutically acceptable salt, derivative, or metabolite thereof is administered at a concentration ranging from about 0.01 mg / kg to about 2 mg / kg of body weight. For example, in some embodiments, the 5-HT4R agonist (e.g., prucalopride), an analog, or a pharmaceutically acceptable salt, derivative, or metabolite thereof is administered at a concentration about, at least, at least about, at most, or at most about 0.01 mg / kg, 0.05 mg / kg, 0.1 mg / kg, 0.2 mg / kg, 0.3 mg / kg, 0.4 mg / kg, 0.5 mg / kg, 0.6 mg / kg, 0.7 mg / kg, 0.8 mg / kg, 0.9 mg / kg, 1.0 mg / kg, 1.2 mg / kg, 1.4 mg / kg, 1.6 mg / kg, 1.8 mg / kg, 2.0 mg / kg, or a number or range between any two of these values, of body weight of the subject.

[0129] In some embodiments, the NMD AR antagonist (e.g., ketamine), an analog, or a pharmaceutically acceptable salt, derivative, or metabolite thereof is administered at a concentration ranging from about 0.01 to about 40 mg / kg of body weight. For example, theconcentration can be at about 0.01 mg / kg, 0.1 mg / kg, 0.5 mg / kg, 1 mg / kg, 1.5 mg / kg, 2.0 mg / kg, 2.5 mg / kg, 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg, 9 mg / kg, 10 mg / kg, 11 mg / kg, 12 mg / kg, 13 mg / kg, 14 mg / kg, 15 mg / kg, 16 mg / kg, 17 mg / kg, 18 mg / kg, 19 mg / kg, 20 mg / kg, 21 mg / kg, 22 mg / kg, 23 mg / kg, 24 mg / kg, 25 mg / kg, 26 mg / kg, 27 mg / kg, 28 mg / kg, 29 mg / kg, 30 mg / kg, 31 mg / kg, 32 mg / kg, 33 mg / kg, 34 mg / kg, 35 mg / kg, 36 mg / kg, 37 mg / kg, 38 mg / kg, 39 mg / kg, 40 mg / kg, or a number or range between any two of these values. In some embodiments, the NMD AR antagonist is administered at a concentration ranging from about 1 mg / kg to about 20 mg / kg, optionally from about 5 mg / kg to about 15 mg / kg.

[0130] In some embodiments, the NMD AR antagonist (e.g., ketamine), an analog, or a pharmaceutically acceptable salt, derivative, or metabolite thereof is administered at a concentration ranging from about 0.5 mg / kg to about 5 mg / kg of body weight. For example, the NMD AR antagonist (e.g., ketamine), an analog, or a pharmaceutically acceptable salt, derivative, or metabolite thereof is administered at a concentration about, at least, at least about, at most, or at most about 0.5 mg / kg, 0.6 mg / kg, 0.7 mg / kg, 0.8 mg / kg, 0.9 mg / kg, 1.0 mg / kg, 1.2 mg / kg, 1.4 mg / kg, 1.6 mg / kg, 1.8 mg / kg, 2.0 mg / kg, 2.2 mg / kg, 2.4 mg / kg, 2.6 mg / kg, 2.8 mg / kg, 3.0 mg / kg, 3.5 mg / kg, 4.0 mg / kg, 4.5 mg / kg, 5 mg / kg or a number of range between any two of these values, of body weight of the subject.

[0131] In some embodiments, the dose of the present composition per administration is from about 1 to about 250 mg, about 10 mg to about 300 mg, about 10 mg to about 250 mg, about 10 to about 200 mg, about 15 to about 175 mg, about 20 to about 175 mg, about 8 mg to about 32 mg, about 50 mg to about 75 mg, about 25 to about 150 mg, about 25 to about 125 mg, about 25 to about 100 mg, about 50 to about 100 mg, about 50 mg to about 75 mg, about 75 mg to about 100 mg, or about 75 mg to about 200 mg, or about 100 mg to about 300 mg, or about 100 mg to about 400 mg, or about 250 mg to about 500 mg.

[0132] In some embodiments, the dose of the present composition or compositions per administration is about 1 mg, 2 mg, 4 mg, 5 mg, 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg, 50 mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, 190 mg, 200 mg, 210 mg, 220 mg, 230 mg, 240 mg, 250 mg, 300 mg, 350 mg, 400 mg, 450 mg, and 500 mg.

[0133] In some embodiments, the dose of the 5-HT4R agonist per administration is about 5 mg, 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg, 50 mg, or a number or range between any two of these values.

[0134] In some embodiments, the dose of the NMD AR antagonist per administration is about 40 mg, 45 mg, 50 mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg, 100 mg, 120 mg, 140 mg, 160 mg, 180 mg, 200 mg, or a number or range between any twoof these values.

[0135] The doses listed above can be the amounts of the individual 5-HT4R agonist or individual NMDAR antagonist. In some embodiments, the doses listed above can be the total amounts of the total 5-HT4R agonist and total NMDAR antagonist. For example, an effective or therapeutically effective amount or dose can comprise about 0.01 to about 40 mg per kilogram of a 5-HT4R agonist and about 0.01 to about 40 mg per kilogram of ketamine. In a further example, an effective or therapeutically effective amount or dose can comprise about 0.01 to about 40 mg per kilogram total of a 5-HT4R agonist combined with ketamine.

[0136] In some embodiments, a single composition contains or comprises both active agents, i.e., 5-HT4R agonist and NMDAR antagonist. In some embodiments, the active agents or compounds are in different compositions. In some embodiments, an effective amount of the ketamine is a sub-anesthetic amount of ketamine, or a pharmaceutically acceptable salt or solvate thereof, or a physiologically functional derivative thereof.

[0137] In some embodiments, the effective or therapeutically effective amount or dose is below the level that results in one or more side effects of the agent. In some embodiments, the effective or therapeutically effective amount or dose can be adjusted depending on conditions of the disease / disorder to be treated or prophetically treated, the age, body weight, general health conditions, sex, and diet of the subject, dose intervals, administration routes, excretion rate, and combinations of drugs.

[0138] In some embodiments, the effective amount of the composition (e.g., the dose of the 5-HT4R agonist and the NMDAR antagonist such as ketamine) can be adjusted depending on the gender of the subject. For example, in some embodiments, the effective amount of the agent administered to a female subj ect is no greater than 90%, no greater than 80%, no greater than 70%, no greater than 60%, no greater than 50%, no greater than 40%, no greater than 30%, no greater than 20%, or no greater than 10%, of an effective amount of the agent administered to a male subject. In some embodiments, the effective amount of the agent administered to a female subject is about 10% to about 90%, about 15% to about 80%, about 20% to about 70%, about 25% to about 60%, about 30% to about 50%, about 30% to about 40%, about 25% to about 40%, about 20% to about 30%, about 25% to about 35%, about 10% to about 30%, about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 20% to about 50%, about 12.5% to about 80%, about 20% to about 70%, about 25% to about 60%, or about 25% to about 50%, about of an effective amount of the agent administered to a male subject.

[0139] In some embodiments, an initial dose is larger, followed by one or more smallermaintenance doses. Other ranges are possible, depending on the subject’s response to the treatment. An initial dose can be the same as, or lower or higher than subsequently administered doses.

[0140] In some embodiments, the effective or therapeutically effective amount or dose can be adjusted depending on the administration route. For example, in some embodiments, the composition is administrated to a subject in need via an intranasal route. The intranasally delivered dose of the pharmaceutical formulation can comprise the agonist of 5-HT4R and NMD AR at a concentration higher than that of the compounds when administered via injection (e.g., intravenously). In some embodiments, the agonist of 5-HT4R and / or the NMDAR are administered intransally at a concentration about or at least about 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or a number or range between any two of these values, higher than the concentration of the compounds when administered via injection.

[0141] The agents, compounds, composition or compositions can be administered daily, weekly, biweekly, several times daily, semi-weekly, every other day, bi-weekly, quarterly, several times per week, semi-weekly, monthly, or more. The duration and frequency of treatment may depend upon the subject’s response to treatment.

[0142] In some embodiments, a subject is administered 1 dose, 2 doses, 3 doses, 4 doses, 5 doses, 6 doses or more of the present agents, compounds, composition or compositions. In some embodiments, a single dose of the present agents, compounds, composition or compositions is administered in the present method. In some embodiments, multiple doses of the present agents, compounds, composition or compositions (e.g., 2 doses, 3 doses, 4 doses, 5 doses, 6 doses, 7 doses, 8 doses, 9 doses, 10 doses or more) are administered in the present method.

[0143] In some embodiments, when there are more than one dose of the present agents, compounds, composition or compositions administered to a subject, the second dose is lower than the first dose. In some embodiments, the second dose is an amount that is at most one-half, one-quarter, or one-tenth the amount of the first dose.

[0144] The number and frequency of doses can be determined based on the subject’s response to administration of the agents, compounds, composition or compositions, e.g., if one or more of the patient’s symptoms improve and / or if the subject tolerates administration of the composition without adverse reaction.

[0145] In some embodiments, the agents, compounds present composition or compositions is administered at least once a day, at least twice a day, at least three times per day, or more. In some embodiments, the agents, compounds, composition or compositions is administered at least once a week, at least twice a week, at least three times per week, or morefrequently. In some embodiments, the present composition or compositions is administered at least twice per month, or at least once per month. Treatment using the present method can continue as long as needed.Dosing Time Frame

[0146] In some embodiments, the 5-HT4R agonist and NMDAR antagonist or the composition or compositions thereof, is administered to a subject prior to a relapse of a stress-induced behavior. In some embodiments, the 5-HT4R agonist and NMDAR antagonist or the composition or compositions thereof, is administered to a subject prior to a relapse of depression or a depression-like behavior. In some embodiments, the composition is administrated to a subject during the early stage of the relapse to prevent the symptoms from worsening. In some embodiments, the composition is administered to a subject prior to and / or after a stressor. In some embodiments, the composition is administered to a subject prior to and / or after a stressor, and again prior to a recurrence of the stressor or a different stressor. In some embodiments, the composition administered to a subject who is currently not experiencing any stress-induced symptom or depression or depression-like symptom, but had previously been treated for such behavior. In some embodiments, the compounds and / or composition is administrated to a subject in remission.

[0147] The compounds and / or composition described herein can be administered to the subject, e.g., about 1 hour to about 5 hours, about 1 hour to about 1 day, about 5 hours to about 10 hours, about 10 hours to about 12 hours, 12 hours to about 1 day, 12 hours to about 4 weeks, about 18 hours to about 4 weeks, about 1 day to about 3.5 weeks, about 2 days to about 3 weeks, about 3 days to about 3 weeks, about 4 days to about 3 weeks, about 5 days to about 3 weeks, about 6 days to about 3 weeks, about 2 days to about 2.5 weeks, about 3 days to about 2.5 weeks, about 4 days to about 2.5 weeks, about 5 days to about 2.5 weeks, about 6 days to about 2.5 weeks, about 1 week to about 2.5 weeks, about 1 week to about 2.5 weeks, about 1 week to about 2 weeks, about 5 minutes to about 3 days, about 10 minutes to about 2 days, about 15 minutes to about 24 hours, about 20 minutes to about 12 hours, about 30 minutes to about 8 hours, about 45 minutes to about 5 hours, about 1 hour to about 12 hours, about 2 hours to about 5 hours, about 5 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 8 hours, about 10 hours, about 12 hours, about 15 hours, about 1 day, about 1.5 days, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 1 week, about 8 days, about 9 days, about 10 days, about 11 days, about 12 days, about 13 days, about 2 weeks, about 2.5 weeks, about 3 weeks, about 3.5 weeks, or about 4 weeks, prior to and / or after a stressor. In some embodiments, the administration to the subject is performed at least once before a stressor and then after astressor.

[0148] In some embodiments, the administration of the compounds and / or composition is continued over a period of up to 2 days, up to 3 days, up to 4 days, up to 5 days, up to 6 days, up to 1 week, up to 2 weeks, up to 3 weeks, up to 4 weeks, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 1 week, about 2 weeks, about 3 weeks, about 4 weeks, about 5 weeks, about 6 weeks, about 7 weeks, about 8 weeks, about 9 weeks, about 10 weeks, or longer.

[0149] In some embodiments, the composition described herein is administered once, twice, at least twice, at least three times, at least four times, at least five time, at least six times, at least seven times, at least eight times, at least nine times, or more per treatment.

[0150] In some embodiments, the composition described herein is administered at least once a day, at least twice a day, at least three times per day, at least once a week, at least twice a week, at least three times a week, at least once per month, at least twice per month, or more frequently. Treatment can continue as long as needed. In some embodiments, the composition is administered at least once before a stressor and at least once after a stressor.

[0151] The composition can be administered daily, weekly, biweekly, several times daily, semi-weekly, every other day, bi-weekly, quarterly, several times per week, semi-weekly, monthly etc. The duration and frequency of treatment may depend upon the subject’s response to treatment.Additional Therapeutics or Therapy

[0152] The present agents, compounds, composition or compositions can be administered to a subject alone, or in combination with one or more additional agents.

[0153] In some embodiments, the additional agent is an anti-depressant, an anxiolytic, or combinations thereof. In some embodiments, the additional agent is a serotonin reuptake inhibitor (SRI), or a selective serotonin reuptake inhibitor (SSRI). In some embodiments, the additional agent is fluoxetine, paroxetine, sertraline, lithium, riluzole, prazosin, lamotrigine, ifenprodil, or combinations thereof. In some embodiments, the additional agent is a dual serotonin norepinephrine reuptake inhibitor compound (DRI). In some embodiments, the additional agent is venlafaxine, duloxetine, milnacipran, or combinations thereof. In some embodiments, the additional agent is a non-tricyclic triple reuptake inhibitor (TRI).

[0154] In some embodiments, the present agents, compounds, composition or compositions are administered to a subject in combination with one or more additional agents such as antidepressants, analgesics, muscle relaxants, anorectics, stimulants, antiepileptic drugs, and sedative / hypnotics. Non-limiting examples of additional agents that can be administered incombination with the present agents, compounds, composition or composition include, but are not limited to, neurontin, pregabalin, pramipexole, L-DOPA, amphetamine, tizanidine, clonidine, tramadol, morphine, tricyclic antidepressants, codeine, carbamazepine, sibutramine, amphetamine, valium, trazodone and combinations thereof.

[0155] In some embodiments, the additional agent is used as adjunctive therapy to the present agents, compounds, composition or compositions. In some embodiments, the treatment includes a phase wherein treatment with the additional agent takes place after treatment with the present agents, compounds, composition or compositions has ceased. In some embodiments, the treatment includes a phase where treatment with the present agents, compound, composition or compositions and treatment with the additional agent / treatment overlap.

[0156] In some embodiments, the additional agents and the composition described herein can be administered to the subject in need simultaneously or sequentially, together or separately. When administered separately this may occur simultaneously or sequentially in any order. The additional agents can be administered in the same dosage form as the composition herein described or in separate dosage forms. The amounts of the present agents, compounds, composition or compositions and the additional pharmaceutically active agent(s) and the relative timings of administration can be selected in order to achieve the desired combined therapeutic effect.

[0157] In some embodiments, a subject is treated concurrently (or concomitantly) with the present agents, compounds, composition or compositions and an additional agent. In some embodiments, a subject is treated initially with the present agents, compounds, composition or compositions, followed by cessation of the present agents, compounds, composition or compositions and initiation of treatment with an additional agent. In some embodiments, the present agents, compounds, composition or compositions are used as an initial treatment, e.g., by administration of one, two or three doses, and an additional agent is administered to prolong the effect of the present agents, compounds, composition or compositions, or alternatively, to boost the effect of the present agents, compounds, composition or compositions. A person of ordinary skill in the art will recognize that other variations of the presented schemes are possible, e.g., initiating treatment of a subject with the present agents, compounds, composition or compositions, followed by a period wherein the subject is treated with an additional agent as adjunct therapy to the present agents, compounds, composition or compositions treatment, followed by cessation of the present agents, compounds, composition or compositions treatment.

[0158] In various embodiments, the therapies (e.g., agents, compounds, composition or compositions provided herein and an additional agent in a combination therapy) are administered less than 5 minutes apart, less than 30 minutes apart, 1 hour apart, at about 1 hourapart, at about 1 to about 2 hours apart, at about 2 hours to about 3 hours apart, at about 3 hours to about 4 hours apart, at about 4 hours to about 5 hours apart, at about 5 hours to about 6 hours apart, at about 6 hours to about 7 hours apart, at about 7 hours to about 8 hours apart, at about 8 hours to about 9 hours apart, at about 9 hours to about 10 hours apart, at about 10 hours to about 11 hours apart, at about 11 hours to about 12 hours apart, at about 12 hours to 18 hours apart, 18 hours to 24 hours apart, 24 hours to 36 hours apart, 36 hours to 48 hours apart, 48 hours to 52 hours apart, 52 hours to 60 hours apart, 60 hours to 72 hours apart, 72 hours to 84 hours apart, 84 hours to 96 hours apart, or 96 hours to 120 hours part. In some embodiments, the therapies are administered no more than 24 hours apart or no more than 48 hours apart. In some embodiments, two or more therapies are administered within the same patient visit. In some embodiments, the agents, compounds, composition or compositions provided herein and the additional agent are administered concurrently. In some embodiments, the agents, compounds, composition or compositions provided herein and the additional agent are administered at about 2 to 4 days apart, at about 4 to 6 days apart, at about 1 week part, at about 1 to 2 weeks apart, or more than 2 weeks apart. In some embodiments, administration of the same agent is repeated and the administrations is separated by at least 1 day, 2 days, 3 days, 5 days, 10 days, 15 days, 30 days, 45 days, 2 months, 75 days, 3 months, or 6 months. In some embodiments, administration of the same agent is repeated and the administration is separated by at least at least 1 day, 2 days, 3 days, 5 days, 10 days, 15 days, 30 days, 45 days, 2 months, 75 days, 3 months, or 6 months.

[0159] In some embodiments, the agents, compounds, composition or compositions provided herein and an additional agent are administered to a subject in a sequence and within a time interval such that the agents, compounds, composition or compositions provided herein can act together with the additional agent to provide an increased benefit than if they were administered otherwise. In some embodiments, the agents, compounds, composition or compositions provided herein and the additional agent exerts their effect at times which overlap. Each additional agent can be administered separately, in any appropriate form and by any suitable route. In some embodiments, the agents, compounds, composition or compositions provided herein is administered before, concurrently or after administration of the second active agent. The additional agent can act additively or synergistically with the agents, compounds, composition or compositions provided herein.

[0160] In some embodiments, the compounds, composition or compositions provided herein is administered concurrently with one or more additional agents in the same pharmaceutical composition. In another embodiment, compounds, composition or compositions composition provided herein is administered concurrently with one or more additional agents in separate pharmaceutical compositions.

[0161] Also contemplated are administration of agents, compounds, composition or compositions provided herein and an additional agent by the same or different routes of administration, e.g., intranasal, oral, or parenteral.Kits

[0162] Also provided herein include kits for use in the present methods for preventing and treating psychiatric disorders including, for example, a depression or depression-like and / or stress-induced disorders or behaviors.

[0163] The kits can include compounds, composition or compositions provided herein, and instructions providing information to a health care provider regarding usage in accordance with the present methods. For example, the kits can comprise (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and an effective amount of (2) an N-methyl-D-aspartate receptor (NMDAR) antagonist, a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof. In some embodiments, the NMDAR antagonist is ketamine or an analog, a derivative or a metabolite thereof. The kit may optionally contain an additional agent or composition. Instructions can be provided in printed form or in the form of an electronic medium such as a floppy disc, CD, or DVD, or in the form of a website address where such instructions can be obtained. A unit dose of agents, compounds, composition or compositions provided herein can include a dosage such that when administered to a subject, a therapeutically or prophylactically effective plasma level of the compound or composition can be maintained in the subject for at least 1 days. In some embodiments, a compound or composition can be included as a sterile aqueous pharmaceutical composition or dry powder (e.g., lyophilized) composition. In some embodiments, suitable packaging is provided. As used herein, “packaging” includes a solid matrix or material customarily used in a system and capable of holding within fixed limits a compound provided herein and / or a second agent suitable for administration to a subject. Such materials include glass and plastic (e.g., polyethylene, polypropylene, and polycarbonate) bottles, vials, paper, plastic, and plastic-foil laminated envelopes and the like.

[0164] The kits can contain one or more containers containing compounds described herein. The compounds described herein can be provided in a same container or different containers. The kits also contain instructions for mixing, diluting, and / or administrating the compounds. The kits also include other containers with one or more solvents, surfactants, preservative and / or diluents (e.g., saline (0.9% NaCl), or 5% dextrose) as well as containers for mixing, diluting or administering the components to a subject in need of such treatment.

[0165] The compositions of the kit can be provided as any suitable form, for example,as liquid solutions, nasal sprays or as dried powders. When the composition provided is a dry powder, the powder can be reconstituted by the addition of a suitable solvent, which may also be provided. In embodiments where liquid forms of the composition are used, the liquid form can be concentrated or ready to use. The solvent will depend on the compound and the mode of use or administration. Suitable solvents for drug compositions are well known and are available in the literature. The solvent will depend on the compound and the mode of use or administration.EXAMPLES

[0166] Some aspects of the embodiments discussed above are disclosed in further detail in the following examples, which are not in any way intended to limit the scope of the present disclosure.Example 1General Methods and Materials

[0167] This example briefly describes the general methods and materials used in Examples 2-8.Mice

[0168] Male and female 129S6 / SvEvTac mice were purchased from Taconic (Hudson, NY) at 7 weeks of age. Mice were housed 5 per cage in a 12-h (06:00-18:00) light-dark colony room at 22 °C. All experiments were approved by the Institutional Animal Care and Use Committee (IACUC) at the New York Psychiatric Institute (NYSPI).Behavioral Assays

[0169] For all experiments, food and water were provided ad libitum, unless otherwise noted. Behavioral testing was performed during the light phase.Contextual Fear Conditioning (CFC)

[0170] A 3-shock CFC paradigm was administered as previously described in Denny, CA et al., Neuron. 2014;83:189-201; Chen, BK, et al., Neuropsychopharmacol. 2020;45:1545- 1556; Chen, BK, et al. Neuropsychopharmacol. 2020;45:542-552; Chen, BK, et al., Biol Psychiatry. 2021;90:458-472. Briefly, CFC was conducted in chambers obtained from Med Associates (St. Albans, VT), with internal dimensions of approximately 20 cm wide x 16 cm deep x 20.5 cm high. The chambers had metal walls on each side, clear plastic front and back walls and ceilings, and stainless-steel bars on the floor. A house light (CM1820 bulb, 28 V, 100 mA) mounted directly above the chamber provided illumination. Each chamber was located inside a larger, insulated, plastic cabinet that provided protection from outside light and noise. Each cabinet contained a ventilation fan that was operated during the sessions. A paper towel dabbed with lemon solution was placed underneath the chamber floor. Mice were held outside theexperimental room in their home cages prior to testing and transported to the conditioning apparatus individually in standard mouse cages. Chambers were cleaned with 70% EtOH between each set of mice. Mice were placed into the conditioning chamber and received shocks at 180 s, 240 s, and 300 s (2 s duration, 0.75 mA). Fifteen seconds after the last shock, mice were removed from the chamber. Overall, the training session lasted 317 s. During re-exposure, mice were placed in the conditioning chamber for 5 minutes and did not receive any shocks. All sessions were scored for freezing using FreezeFrame4.Learned Helplessness (LH)

[0171] Learned helplessness was performed as previously described in Chen, BK, et al., Neuropsychopharmacol. 2020; 45:1545-1556; Brachman, Biol Psychiatry. 2016; 79:776-786. The procedure was conducted in a two-chamber shuttle box (model ENV 010MD; Med Associates, St. Albans, VT) located within a sound-attenuated cubicle. The grid floor was made of stainless steel and connected to a shock generator. The scrambled shock generator (model ENV 414S, Med Associates, St. Albans, VT) created varying electrical potential differences between bars preventing an animal from avoiding shock.

[0172] Inescapable shock (training)'. At approximately 8 weeks of age, mice were trained in the LH paradigm. For each shuttle box, 2 animals were administered the protocol at the same time; the central door was closed, with one animal in each side's chamber. After a 3 min habituation period, the shock deliveries began. The training protocol consisted of 70 shocks, each with a 3 s average duration, at 0.5 mA, and with an intertrial interval (ITI) of approximately 15 s.

[0173] Shock escape (testing): Mice were tested in the same shuttle box used in the inescapable shock training. The box consisted of two identical chambers (17 1 x 20 w x 17 h), separated by an automated door that opened vertically. The shuttle box was equipped with 8 infrared beams (4 on each side) for detecting position and activity of the animal (Med Associates, St. Albans, VT). Each mouse was placed into the right chamber with the door raised and was allowed to freely explore both chambers for 3 minutes. The door then closed automatically.

[0174] At the beginning of each trial, the door was raised and 5 s later a foot shock (0.5 mA) was delivered. The subject's exit from the shocked side ended the trial. If the mouse did not exit after 15 s, the shock was turned off and the trial ended. The door was lowered at the end of the trial. A session consisted of 30 trials separated by a 30 s ITI. Escape latencies were computed as the time from shock onset to the end of trial. If the subject failed to make a transition, the maximum 15 s was used for the escape latency score.Stress-Enhanced Fear Learning (SEFL)

[0175] The SEFL procedure is a rodent stress model designed to investigate non-associative fear sensitization, a critical symptom of post-traumatic stress disorder (Nishimura, KJet al., Neurosci Biobehav Rev. 2022; 142: 104884; Rau, V et al., Stress AmstNeth. 2009; 12: 125-133; Rau, V et al., Neurosci Biobehav Rev. 2005;29:1207-1223; Long, VA et al., Stress.2012;15:627-636). Here, a modified version of a previously published paradigm was used (Hassien, AM et al., Behav Brain Res. 2020; 379:112391). The procedure was conducted in the same fear conditioning boxes used for CFC. Scents were applied to a paper towel in the waste tray below the chamber floor. Mice were held outside the experimental room in their home cages prior to testing and transported to the conditioning apparatus individually in standard mouse cages. Chambers were cleaned with 70% EtOH between each set of mice. All sessions were scored for freezing using FreezeFrame4.Context A:

[0176] Mice received footshock stress in Context A. The chamber consisted of metal walls on each side, clear plastic front and back walls, and stainless steel bars on the floor. The chamber was scented with lemon solution. A house light (CM1820 bulb, 28 V, 100 mA) mounted directly above the chamber provided illumination during the protocol. During training, mice were placed into the conditioning chamber and received shocks at 160 s, 240 s, 320 s, and 400 s (2 s duration, 0.75 mA). Seventy seconds after the last shock, mice were removed from the chamber. Overall, the training session lasted 480 s. Freezing was scored throughout and divided into 60-s intervals. During subsequent re-exposures, mice were returned to Context A for 5 min.Context B:

[0177] Mice received tone-shock training in Context B. The chamber consisted of metal walls on each side, clear plastic front and back walls, and blue plastic inserts on the floor. The chamber was scented with anise solution. A house light (CM1820 bulb, 28 V, 100 mA) mounted directly above the chamber provided illumination during the protocol. Mice were placed into Context B, and a tone (30 s, 90 dB, 9 kHz) was played three times with 30-s interstimulus intervals. Mice were removed 30 s after the final tone. Overall, the session lasted 210 s. Freezing was scored throughout and divided into 30-s intervals. For analysis, freezing before the tones (PreTone) and after the final tone (Post-Tone) was presented. Additionally, freezing during the tone presentation (CS) and between trials (ITI) was averaged. The discrimination score was calculated using the following formula:Discrimination score = Mean CS freezing) — (Mean ITI freezing) Context C:

[0178] Mice received single-shock contextual fear conditioning in Context C. The chamber consisted red plastic circular walls, and stainless-steel bars on the floor. The chamber was scented with almond solution. A red light (28 V, 100 mA) provided illumination during the protocol, and mice were run in the dark. Mice were placed into Context C and received a singlefootshock (2 s duration, 0.75 mA) at 180 s. Mice were removed 30 s after the shock. Overall, the session lasted 212 s. Freezing was scored throughout and divided into 60-s intervals. During subsequent re-exposures, mice were returned to Context A for 3 min.Chronic Corticosterone (CORT)

[0179] In this model, glucocorticoid levels are exogenously increased in C57BL / 6J mice. This chronic CORT elevation dysregulates the hypothalamic-pituitary-adrenal axis (HP A) in a manner similar to that observed in clinical depression. Chronic CORT was administered as previously described in Chen, BK, et al. Neuropsychopharmacol. 2020; 45:542-552; Mendez-David, I et al., Neuropsychopharmacol. 2014; 39:1366-1378; David, DJ et al., Neuron. 2009; 62:479-493; Lebedeva, KA et al., Physiol Behav. 2020; 224:113070; Mekiri, M et al., Exp Clin Psychopharmacol. 2017; 25:94-104. Briefly, CORT (35 pg / ml, equivalent to about 5 mg / kg / day) dissolved in 0.45% hydroxypropyl-p-cyclodextrin (P-CD) or vehicle (Veh) (0.45% P-CD) was available ad libitum in the drinking water in opaque bottles to protect it from light. Veh- and CORT-treated water was changed every 3 days to prevent possible degradation.Forced Swim Test (FST)

[0180] The FST was administered as previously described in Chen, BK, et al., Neuropsychopharmacol. 2020; 45:1545-1556; Chen, BK, et al. Neuropsychopharmacol. 2020; 45:542-552; Chen, BK, et al., Biol Psychiatry. 2021; 90:458-472; Brachman, Biol Psychiatry.2016; 79:776-786. Briefly, mice were placed into clear plastic buckets 20 cm in diameter and 23 cm deep filled 2 / 3 of the way with 22°C water. Mice were videotaped from the side for 6 min and were exposed to the swim test on 2 consecutive days. Immobility time was scored by an experimenter blind to the experimental groups.Open Field (OF)

[0181] The OF assay was administered as previously described in Chen, BK, et al., Biol Psychiatry. 2021; 90:458-472. Briefly, motor activity was quantified in 4 open field boxes 43 x 43 cm2(MED Associates, Georgia, VT). An overhead camera was used to track locomotor activity. Activity chambers were computer interfaced for data sampling at 100-ms resolution. The computer defined grid lines that dividing center and surround regions, with the center square consisting of four lines 11 cm from the wall.Elevated Plus Maze (EPM)

[0182] Testing was performed as previously described in Chen, BK, et al., Neuropsychopharmacol. 2020; 45:1545-1556; Chen, BK, et al. Neuropsychopharmacol. 2020; 45:542-552; Chen, BK, et al., Biol Psychiatry. 2021; 90:458-472. Briefly, the maze is a plus-cross-shaped apparatus consisting of four arms, two open and two enclosed by walls, linked by a central platform at a height of 50 cm from the floor. Mice were individually placed in the centerof the maze facing an open arm and were allowed to explore the maze for 5 min. The time spent in and the number of entries into the open arms was used as an anxiety index. Videos were scored using ANY-maze behavior tracking software (Stoelting, Wood Dale, IL).Marble Burying (MB)

[0183] The MB assay was conducted in a clean cage (10.5 in x 5.5 in) containing soft pliable Beta Chip bedding (Northeastern Products Corp, Warrensburg, NY). The cage contained 16 marbles set up in 4 rows of 4 across. Mice were given 30 minutes to explore and bury. At the end of the assay, the percentage of marbles buried was calculated.Novelty Suppressed Feeding (NSF)

[0184] Testing was performed as previously described in Chen, BK, et al. Neuropsychopharmacol. 2020; 45:542-552; Chen, BK, et al., Biol Psychiatry. 2021; 90:458-472. Briefly, the NSF testing apparatus consisted of a plastic box (50 x 50 x 20 cm), the floor of which was covered with approximately 2 cm of wooden bedding and the arena was brightly lit (approximately 1000 lux). Mice were food restricted for 12hfor 129S6 / SvEv mice prior to testing. At the time of testing, a single pellet of food (regular chow) was placed on a white paper platform positioned in the center of the box. Each animal was placed in a comer of the box, and a stopwatch was immediately started. The latency of the mice to begin eating in the arena was recorded. Immediately after the latency was recorded, the food pellet was removed from the arena. The mice were then placed back into their home cage. The latency to eat and the amount of food consumed in 5 min were measured (home cage consumption), followed by an assessment of post-restriction weight. A Kaplan-Meier survival analysis was used due to the lack of normal distribution of data. The Mantel-Cox log-rank test was used to evaluate differences between the experimental groups.Sucrose Splash Test (SST)

[0185] This test consisted of squirting 200 pl of a 10% sucrose solution on the mouse’s snout (Chen, BK, et al. Neuropsychopharmacol. 2020; 45:542-552). The grooming duration was quantified using Stopwatch+ (Center for Behavioral Neuroscience, Georgia State University) by an experimenter blind to the experimental groups.Immunohistochemistry

[0186] Immunohistochemistry was performed as previously described in Denny, CA et al., Neuron. 2014; 83:189-201; Chen, BK, et al., Biol Psychiatry. 2021; 90:458-472; Ghibaudi, M et al., Int J Mol Sci. 2023;24:2514. Mice were deeply anesthetized, and brains were fixed and extracted using transcardial perfusion. For all immunohistochemistry, floating sections were used.Glial fibrillary acidic protein (GFAP) immunohistochemistry

[0187] Sections were first rinsed 3 times in IX phosphate buffered saline (PBS) and then blocked in IX PBS with 0.1% Triton X-100 (PBST), 10% normal donkey serum (NDS), and0.1% glycine for 1 hour at room temperature (RT). Incubation with primary antibodies was performed at 4 °C overnight (polyclonal rabbit anti-glial fibrillary acidic protein (GFAP), GA524, 1:500, Agilent (Dako Omnis), Santa Clara, CA) in IX PBS with 0.1% Tween-20. Sections were then washed 3 times in IX PBS and incubated with secondary antibody (Alexa 488 anti-rabbit, A-21206, 1:250, Thermo Fisher Scientific, Waltham, MA) in IX PBS with 0.1% Tween-20 and 5% NDS for 2 hours at RT. Sections were then washed three times in IX PBS, mounted on slides, and coverslipped with Fluoromount G (Electron Microscopy Sciences, Hatfield, PA).Ki67 immunohistochemistry

[0188] Sections were first rinsed 3 times in 1 x phosphate buffered saline (PBS) and then quenched in a 1:1 solution of IX PBS and methanol with 0.3% H2O2 for 15 minutes at RT. Sections were then washed three times in IX PBS. Sections were blocked in IX PBS with 0.2% Triton X-100, 2% NDS, and 2% bovine serum albumin (BSA) for 90 minutes. Incubation of primary antibody was performed at 4°C overnight (rabbit anti-Ki67, abl5580, 1:500, Abeam, Cambridge, UK) in blocking solution. Sections were subsequently washed 3 times in IX PBS and incubated with secondary antibody (Cy5 anti-rabbit, 111-175-144, Jackson ImmunoResearch, West Grove, PA) with IX PBS with 0.2% Tween-20 and 3% NDS for 2 hours at RT. Sections were then washed three times in IX PBS, mounted on slides, and coverslipped with Fluoromount G (Electron Microscopy Sciences, Hatfield, PA).Confocal Microscopy

[0189] Fluorescent confocal micrographs were captured with a Leica TCS SPE-II confocal microscope with LAS X software as previously described in Chen, BK, et al., Biol Psychiatry. 2021; 90:458-472. Bilateral hippocampal sections were imaged throughout the rostro-caudal axis of the HPC using a 20X objective. Identification of hippocampal regions involved acquiring 3-4 dorsal and ventral sections per mouse brain slice at 20X. All individual panels were acquired at a thickness of 3 pm. Z-stack analysis was performed using the LAS X image browser to determine expression of c-fos and PV. Expression levels of GFAP were compared across all sections using identical exposure conditions.Cell Quantification

[0190] An investigator blind to treatment groups used automated Fiji software to quantify bilateral GFAP fluorescent expression in DG, CA3, and CAI throughout the entire rostrocaudal axis of the HPC. GFAP fluorescence per pm2is presented throughout the text. An investigator blind to treatment groups used Fiji software to hand count bilateral Ki67 expression in DG. Number of Ki67+cells per section is presented throughout the text.Statistical Analysis

[0191] Data were analyzed using Prism 10 (Graphpad Software, La Jolla, CA). Alphawas set to 0.05 for all analyses. Generally, the effect of Drug or Group was analyzed using an analysis of variance (ANOVA), using repeated measures where appropriate. Post-hoc Sidak, or Tukey tests were used where appropriate.Drugs

[0192] Saline (0.9% NaCl) (Sal), (A,5)-ketamine (K) (Ketaset, Zoetis, Parsippany-Troy Hills, NJ), prucalopride (P) (SML1371, Sigma-Aldrich, St. Louis, MO), or combined (R,S)-ketamine + prucalopride (K+P) was administered at varying intervals starting at approximately eight weeks of age. For intraperitoneal (i.p.) injections, all drugs were prepared in physiological saline and administered in volumes of 0.1 cc per 10 mg body weight. For intranasal administration, drugs were prepared in a mixture of 25% dimethyl sulfoxide (DMSO) and 75% physiological saline and administered in volumes of 1 pl per 1 g body weight. Intranasal drug administration was performed in awake mice using a micropipette. Sal and P (0.75, 1.5, or 3 mg / kg) were administered daily. (A,S)-ketamine (K) (10 or 30 mg / kg) was administered once or twice per week. For combined K+P, K (10 mg / kg) was administered twice per week and P (0.75, 1.5, or 3 mg / kg) was administered daily. K was only administered, at most, twice per week to avoid inducing schizophrenia-like behaviors in mice. To control for injection or intranasal administration stress, mice were administered Sal on days when K was not administered.Example 2Chronic intraperitoneal administration of (R,S)-ketamine + prucalopride attenuates stress-related maladaptive behaviors in male mice

[0193] This example aimed to evaluate whether chronic administration of (R,S)-ketamine and prucalopride (K+P) can attenuate additional stress-induced behaviors than when administered alone. Male 129S6 / SvEv mice were first exposed to 3-shock CFC and subsequently administered chronic i.p. injections of saline, K, P, or combined K+P (1, 2, or 7x per week). Two weeks later, mice were administered CFC re-exposure, the forced swim test (FST), and marble burying (MB) assays. Drug administration continued throughout the behavioral assays (FIG. 1A).

[0194] Freezing during CFC training was comparable across groups (FIG. IB).During CFC re-exposure, K+P (10 mg / kg, 2X + 1.5 mg / kg, 7X, respectively) significantly attenuated freezing in comparison to Sal (FIG. 1C). There were no other significant comparisons between drug groups. On FST day 1, immobility time was comparable across all drug groups (FIG. ID). During FST day 2, K (30 mg / kg, 2X) and K+P (10 mg / kg, 2X + 1.5 mg / kg, 7X, respectively) significantly reduced immobility when compared with Sal (FIG. IE). During the MB assay, both tested doses of K+P significantly reduced the number of marbles buried when compared with Sal (data not shown). K + P (10 mg / kg, 2X+ 1.5 mg / kg, 7X, respectively) also reduced immobility in comparison to K (10 mg / kg, 2X).

[0195] To determine if chronic drug injections affected changes in weight, mice were weighed daily. Changes in weight and appetite are common symptoms of MDD that may be related to changes in the neurocircuitry underlying interoception and reward processing. Additionally, many currently available antidepressants, including SSRIs, exhibit nonspecific effects on weight and appetite. Mice administered K (30 mg / kg, IX), but no other drug, had significantly increased weight gain in comparison to Sal (FIG. IF). As Sal-administered mice exhibited a reduction in body weight over the 2-week treatment, it may be that this K-induced increase in body weight is not an adverse side effect but rather represented a sustained normalization of body weight over the course of treatment. Findings in this Example indicate that chronic K+P effectively reduces fear, behavioral despair, and perseverative behaviors without significantly altering weight changes in male mice, suggesting that chronic administration of an NMD AR antagonist and 5-HT4R agonist may be a safe and effective antidepressant combination.Example 3Chronic intranasal administration of combined (R,S)-ketamine + prucalopride reduces behavioral despair in male mice

[0196] This example aimed to evaluate whether an alternative administration of drug could be effective following stress exposure. Intranasal drug delivery is a promising alternative method to delivering therapeutic agents for neurological and psychiatric disorders, such as depression and Alzheimer’s disease (AD). To test the potential efficacy of intranasal delivery of K+P, the same behavioral and drug administration paradigm were administered to male mice as previously described in FIG. 1A, with the exception that mice were given intranasal drug administration (FIG. 2A).

[0197] Chronic intranasal drug administration did not significantly alter behavior during CFC training, CFC re-exposure, or FST day 1 (FIGS. 2B-2D). During FST day 2, P (0.75 mg / kg, 7X) and K+P (10 mg / kg, 2X + 1.5 mg / kg, 7X, respectively) significantly reduced immobility time when compared with Sal (FIG. 2E). Marble burying was not significantly affected by drug administration (data not shown). K (10 mg / kg, 2X) and P (0.75 mg / kg, 7X) significantly increased weight gain in comparison to Sal, while K+P (10 mg / kg, 2X +1.5 mg / kg, 7X, respectively) attenuated the weight gain induced by K (10 mg / kg, 2X) administration (FIG.2F). Since Sal-administered mice exhibited an overall decrease in body weight, K- and P-induced changes in weight could represent a normalization of body weight following stress, rather than adverse nonspecific side effects. These data indicate that chronic administration of an NMD AR antagonist and 5-HT4R agonist may also be given intranasally, offering multiple options for drug delivery.Example 3Chronic administration of (R,S)-ketamine + prucal opride attenuates behavioral despair in female mice

[0198] This example aimed to determine if chronic K+P would be effective in suppressing stress-induced behaviors in female mice. Female 129S6 / SvEv mice were administered the same experimental timeline outlined in FIG. 1 and FIG. 8A. As it has been previously shown that lower doses of K and P are more effective in female mice, as compared to male mice, higher doses of K or P alone were not tested. While behavior was not significantly different between groups during CFC training (FIG. 8B), CFC re-exposure (FIG. 8C), or FST day 1 (FIG. 8D), drug administration significantly altered immobility time on FST day 2 (FIG.8E). Specifically, P (0.75 mg / kg, 7X) and K+P (10 mg / kg, 2X + 1.5 mg / kg, 7X, respectively) significantly reduced immobility in relation to Sal. Once again, female mice were weighed daily to monitor changes in weight gain. K (10 mg / kg, IX), but not other drug groups, significantly reduced weight gain when compared with Sal (FIG. 8F). Together, these findings suggest that chronic, combined administration of K+P attenuates behavioral despair when given after stress in female mice.

[0199] Next, intranasal drug delivery in female mice was investigated as described in FIG. 2A and FIG. 9A. Chronic intranasal drug administration did not significantly alter behavior during CFC training (FIG. 9B), CFC re-exposure (FIG. 9C), or FST day 1 (FIG. 9D). On FST day 2, both doses of K+P significantly reduced immobility when compared with Sal. K+P (10 mg / kg, 2X + 1.5 mg / kg, 7X, respectively) also significantly reduced immobility when compared to K (10 mg / kg, 2X) and P (1.5 mg / kg, 7X) (FIG. 9E). Change in weight was not significantly altered between drug groups (FIG. 9F). Overall, our results suggest that intranasal administration of combined K+P, at a specific drug dose, is effective in reducing behavioral despair in both sexes, suggesting that this drug combination may exhibit antidepressant efficacy when administered via intranasal delivery.Example 4Chronic administration of (R,S)-ketamine + prucalopride suppresses behavioral despair following stress-enhanced fear learning stress in both sexes

[0200] This example is for testing the efficacy of K+P in a more severe model of stress. In particular, it aimed to use stress-enhanced fear learning (SEFL), which has emerged as a rodent model of post-traumatic stress disorder (PTSD). Notably, this behavioral assay uses aspects of Pavlovian fear conditioning to recapitulate the long-term sensitization of fear learning induced by exposure to a prior stressor, a critical symptom of PTSD. Here, a modified version of SEFL that is specialized for use in 129S6 mice was used. First, mice were administered 4 footshocks in Context A, which served as a traumatic exposure (FIG.3A). A control group of mice received nofootshocks in Context A. Mice were then re-exposed to Context A, to test their fear response, and subsequently administered an unconditioned tone fear test in Context B. Mice were then administered two weeks of chronic i.p. drug administration as previously described. After two weeks of drug administration, mice were administered 1-shock CFC and re-exposure in a third Context C, re-exposed to Context A, then underwent re-exposure to tone fear testing in Context B. In this behavioral assay, behavior during Context B re-exposure was used to measure learned fear behavior that was sensitized following the footshock stress administered in Context A. In particular, freezing during the tones (i.e., conditioned stimuli (CS)) was compared with freezing during intertrial intervals (ITIs). Following SEFL, mice were administered additional behavioral assays.

[0201] In male mice, freezing during Context C training and re-exposure was comparable in all groups (FIGS. 3B-3C). In Context A re-exposure 2, freezing in mice administered K (10 mg / kg, IX) or K (30 mg / kg, 2X) was significantly higher when compared with non-stressed saline-administered mice (FIG. 3D). During Context B re-exposure, behavior was comparable between all groups, including mean retrieval discrimination (FIG. 3E), average freezing during tone presentations (FIG. 3F), and average freezing during intertrial intervals (FIG. 3G). However, although immobility time was comparable between all groups during FST day 1 (FIG. 3H), K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly reduced immobility on FST day 2 in comparison to Sal (FIG.31). There was a trending, but not significant, decrease in marbles buried in mice administered K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) when compared with Sal (FIG. 3J). Exposure to stress and drug administration did not significantly impact behavior in the EPM, OF, or changes in weight (Table 1; FIG. 3K).Altogether, our findings indicate that chronic administration of K+P significantly reduces behavioral despair, but does not alter other stress-induced behaviors, following SEFL in male mice.

[0202] Next, SEFL in female mice (FIG. 4A) was performed. Behavior was comparable during Context C training and re-exposure (FIGS. 4B-4C). Mice administered K (10 mg / kg, IX) froze significantly more than non-stressed mice administered Sal (FIG. 4D) during Context A re-exposure 2. All behavioral measures were comparable during Context B re-exposure (FIGS. 4E-4G) and on FST day 1 (FIG. 4H). On FST day 2, K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly attenuated immobility time when compared with Sal (FIG. 41). Drug administration and stress exposure did not significantly impact behavior in the MB assay, EPM, or OF, and body weight change was comparable across all groups (Table 1; FIGS. 4J-4K). These results suggest that, similarly to male mice, chronic administration of K+P significantly reduces behavioral despair, but does not impact other stress-induced behaviors, following SEFL stress infemale mice.Example 5Chronic intranasal (R,S)-ketamine + prucal opride reduces fear behavior in male mice and suppresses behavioral despair in female mice following SEFL stress

[0203] Similar to CFC, this example sought to determine if intranasal delivery of K+P could be effective following SEFL. The same behavioral paradigm as described in FIG. 3 was repeated, but the drugs were administered using intranasal delivery (FIG. 10A). In male mice, behavior was comparable across all groups during Context C training, Context C re-exposure, and Context A re-exposure 2 (FIGS. 10B-10D). Although mean retrieval discrimination and freezing during CS presentations was comparable between the groups (FIGS. 10E-10F), freezing during ITIs was significantly attenuated in mice administered K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) when compared to non-stressed mice administered Sal (FIG. 10G). There was also a trending, but not significant, decrease in freezing compared to Sal in mice given K (10 mg / kg, IX). In the FST, behavior was comparable between all groups (FIGS. 10H-10I). Marbles buried in the MB assay was not significantly impacted by drug administration (FIG. 10J). Mice administered K (10 mg / kg, IX) or P (3 mg / kg, 7X) traveled significantly more than saline controls in the EPM (Table 1). All other behavior in the EPM and OF as well as change in body weight was comparable between groups (FIG. 10K). These findings suggest that combined intranasal K+P may attenuate SEFL in male mice but does not impact other behaviors induced by SEFL.

[0204] SEFL was next administered to female mice (FIG. 11, Panel A). Fear behavior (FIG. 11, Panels B -G) and immobility time on FST day 1 (FIG. 11, Panel H) were not significantly impacted by intranasal drug administration. However, on FST day 2, K (10 mg / kg, IX or 2X) and K+P (10 mg / kg, 2X + 0.75 mg / kg, 7X, respectively) significantly reduced immobility time when compared with Sal (FIG. 41). While behavior during the MB assay and EPM (FIG. 11, panel J) were not affected by drug administration, P (1.5 mg / kg, 7X) significantly increased distance traveled in the OF. Intranasal K (30 mg / kg, 2X) significantly reduced weight gain in comparison to Sal (FIG. 11, panel K). These results suggest that intranasal K+P in female mice does not alter SEFL behavior but may suppress SEFL-induced behavioral despair.Example 6Chronic prucalopride increases GFAP expression in CAI

[0205] This example sought to determine how chronic drug administration changes markers of neurogenesis and astrocyte reactivity in the brain due to extensive previous literature indicating the involvement of these mechanisms in the antidepressant effects of ketamine and drugs. Using the same cohort of SEFL mice tested in FIG. 3 and FIG. 10, mice were euthanized, and brains were collected following the OF. Brain sections from mice administered Sal, K (10mg / kg, 2X), P (3 mg / kg, 7X), or K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) were chosen. Then immunohistochemistry was used to quantify glial fibrillary acidic protein (GFAP), a marker expressed in astrocytes and neural stem cells (NSCs) (FIG. 12) and Ki67, a nuclear protein expressed at all phases of the cell cycle except for the resting phase (FIG. 13). GFAP expression was comparable in all hippocampal regions quantified except for dorsal CAI (FIG. 12, panels A-G). In dorsal CAI, P (3 mg / kg, 7X) significantly increased GFAP expression in comparison to all other groups (FIG. 12, panel D). Ki67 expression was comparable across all drug groups (FIG.13, panels A-C). These findings suggest that while chronic P selectively enhances GFAP expression in dorsal CAI, chronic K+P does not significantly alter adult hippocampal neurogenesis or astrocyte reactivity in the hippocampus as measured by GFAP and Ki67 expression.Example 7Chronic administration of (R,S)-ketamine + prucalopride is effective following learned helplessness in male and female mice

[0206] Learned helplessness (LH), is a commonly used and well-validated animal model of depression that exhibits construct, face, and predictive validity. Male mice were first administered LH training and subsequently given two weeks of chronic i.p. injections of Sal, K, P, or K+P (FIG. 5A). Mice were then administered LH testing, FST, OF, MB, EPM, and NSF assays.

[0207] During LH testing, K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) resulted in a trending reduction in the latency to escape in comparison to Sal (FIG. 5B). This behavioral measure was significantly reduced when compared with mice administered K (10 mg / kg, 2X). On both days of the FST, immobility time was comparable across all drug groups (FIGS. 5C-5D).K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly reduced the numbers of marbles buried during the MB assay (FIG. 5E). In the NSF, mice administered P (3 mg / kg, 7X) and K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) exhibited significantly reduced latency to feed in the novel arena when compared with Sal (FIGS. 5F-5G). Behavior in the OF and EPM, and weight was not significantly impacted by drug administration (Table 1).

[0208] LH was next administered to female mice (FIG. 6A). Behavior during LH testing and on FST day 1 was comparable across all drug groups (FIGS. 6B-6C). During FST day 2, K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively) significantly reduced immobility time when compared to Sal (FIG. 6D). MB was comparable across all drug groups (FIG.6E). In NSF, while there was a significant effect of drug during a survival curve analysis, there were no significant comparisons when performing a one-way ANOVA (FIGS. 6F-6G). Altogether, these results indicate that K+P effectively suppresses behavioral despair in female mice as well as perseverativeand hyponeophagia behaviors in male mice following LH.Example 8Chronic K+P prevents relapse of depression-like behaviors in male mice

[0209] This example sought to test whether chronic K+P could attenuate maladaptive behaviors in a rodent model of recurrent depression. As depression is a chronic and highly recurrent disorder, many patients experience relapse of a depressive episode despite previously receiving treatment and achieving remission. To model this herein, a modified version of chronic, cyclical corticosterone (CORT) administration, a neuroendocrine model of stress, was used. Male C57BL / 6NTac mice were administered 4 weeks of a control vehicle (Veh) or chronic CORT in the drinking water to induce depression (FIG. 7A). Female mice were not tested in this paradigm, as a previous finding showed that chronic CORT does not significantly impact behavior in female C57BL / 6 mice. Mice were then given two weeks of chronic i.p. Sal, K, P, or K+P injections and tested in the sucrose splash test (SST), MB, and NSF assays to quantify grooming, perseverative, and hyponeophagia behaviors, respectively. This phase of the paradigm was used to mimic an initial antidepressant treatment phase. Next, to model a remission phase, i.p. drug injection continued, but mice were taken off CORT, and the SST, MB, and NSF tests were administered. Finally, drug administration was halted, and mice were placed back on CORT. Once again, the SST, MB, and NSF tests were administered; this phase of the behavioral paradigm was used to model relapse of a depressive episode.

[0210] During the treatment phase, as expected, chronic CORT administration significantly reduced grooming behavior in comparison to Veh (FIG. 7B). This reduction in grooming was rescued by administration of chronic K+P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively), but no other drug, and this rescue was comparable to Veh + Sal control mice. K + P (10 mg / kg, 2X + 3 mg / kg, 7X, respectively)-administered mice also exhibited significantly higher grooming than K (10 mg / kg, 2X) and P (FIG. 7B). Behavior in the MB assay was comparable across all groups (FIG.7C). In the NSF, P (3 mg / kg, 7X) significantly reduced the latency to feed in comparison to CORT + Sal-administered mice (FIGS. 7D-7E). These findings suggest that chronic K+P injection, but not either drug alone, rescues CORT -induced impairments in grooming behavior.

[0211] During the remission phase, it was observed that chronic K+P, but not K or P alone, restored impairments in grooming bouts induced by CORT administration, comparable to Veh controls (FIG. 7F). Once again, there was no change in perseverative behavior between the groups during the MB assay (FIG. 7G). During the NSF, CORT induced a trending increase in feeding latency. There was a trending reduction in feeding latency in P-administered mice as well as a significant reduction in feeding latency in K+P-administered mice, when compared with theCORT + Sal mice (FIGS. 7H-7I). Altogether, these findings suggest that chronic CORT results in long-lasting impairments in grooming and hyponeophagia behaviors, and that chronic K+P administration may rescue these changes.

[0212] During the relapse phase, it was once again found that chronic K+P, but no other drug, rescued CORT -induced reductions in grooming behavior, comparable to Veh controls (FIG. 7J). Behavior in the MB test was comparable across all groups (FIG. 7K). CORT administration, in comparison to Veh controls, significantly increased latency to feed in the NSF (FIGS. 7L-7M). This increase in feeding latency was suppressed in P and K+P-administered mice. Overall, our findings indicate that chronic K+P can prevent the relapse of CORT -induced impairments in grooming and hyponeophagia behaviors in male mice.Additional Considerations

[0213] In this study, the effects of chronic i.p. and intranasal administration of combined K+P in a variety of rodent stress models were characterized. The experiments show that 1) chronic i.p. administration of K+P attenuates a variety of learned fear, behavioral despair, perseverative, and hyponeophagia behaviors following footshock stress in male mice, 2) chronic intranasal K+P suppresses behavioral despair following a variety of stressors in male mice, 3) chronic i.p. and intranasal K+P reduces behavioral despair induced by a variety of stressors in female mice, and 4) chronic K+P prevents relapse in a mouse model of recurrent depression. Overall, these findings suggest that adjunctive administration of an NMD AR antagonist and 5-HT4R agonist can have rapid, long-lasting therapeutic benefits. A full summary of experimental findings can be found in FIG. 14.

[0214] The experimental results described above indicate that while K or P alone suppress some maladaptive behaviors, K+P delivers a more consistent therapeutic benefit in multiple models of stress. These findings suggest that adjunctive drug therapy to target both NMDARs and S-FFDRs may be more efficacious at combating a wider range of stress-related psychiatric disorders than monotherapy. As MDD is a heterogeneous and complex disorder, it is perhaps unsurprising that targeting multiple receptors in the brain may have added benefits. Indeed, clinical data demonstrate that adjunctive pharmacological therapy, such as Spravato® (CS'j-ketamine) in combination with SSRI administration, is particularly effective in treatment-resistant depression. Further evidence suggests that augmentation or combination therapy can have synergistic effects even in partial responders. Moreover, in addition to enhancing treatment efficacy, combination pharmacotherapy may lead to improved treatment outcomes in comparison to monotherapy.

[0215] The experiments conducted herein also found that chronic K+P can exertextended therapeutic benefits to prevent depression relapse. According to clinical guidelines, pharmacological treatment for depression may be separated into distinct phases. During an acute depressive episode, treatment with an approved antidepressant medication in a responsive patient can allow for progression to full remission. Here, patients enter a continuation phase, in which medication is continuously administered for several months. Subsequently, patients may be gradually tapered off medication, as rapid discontinuation of treatment can lead to a symptomatic relapse. Regardless of adherence to these guidelines, the risk of relapse is extremely high, with an estimated rate of up to 60% of patients at risk of developing recurrent depressive episodes. Thus, it is imperative to develop treatments that can not only lead to remission but also prevent future relapse of depressive episodes. In the present study, chronic i.p. K+P attenuated CORT-induced impairments in grooming and stress-related feeding behavior in all phases, suggesting that this combinatorial drug treatment can provide rapid antidepressant-like action and prevent the relapse of a depressive episode, even after discontinuing administration.

[0216] The present study also tested the efficacy of chronic intranasal administration of K+P. Intranasal drug delivery provides certain advantages that are critical for disorders of the central nervous system (CNS), such as enhanced and more rapid bioavailability in the brain, reduced side effects in peripheral organs, and the elimination of first-pass hepatic metabolism, all of which may be attributed to bypassing of the blood-brain barrier. Additionally, intranasal delivery is non-invasive and may be easily self-administered, which provides further advantages for patients requiring chronic drug treatment. Unexpectedly, it was found that intranasal and i.p. drug delivery exhibits distinct behavioral effects when chronically administered after stress. However, although intranasal K+P did not attenuate the wide variety of stress-induced behaviors that we observed following i.p. K+P, intranasal administration did reliably reduce behavioral despair in both male and female mice in two separate models of stress. Without being bound by any particular theory, it is believed that the neurobiological circuits mediating fear and anxietylike behaviors are distinct from those mediating behavioral despair and that hepatic breakdown of K and P results in metabolic intermediate compounds that are critical for targeting these fear / anxiety circuits. It is also believe that activation of peripheral targets, such as stimulation of the gut-brain axis via the vagus nerve, could also have contributed to the therapeutic effects of systemic drug administration. Thus, i.p., but not intranasal, K+P can attenuate a wider variety of stress-induced maladaptive behaviors, but both methods of delivery still effectively reduce behavioral despair. Our experimental findings provide evidence that intranasal delivery of K+P can have therapeutic efficacy against depression and as an intranasal treatment option for psychiatric disorders.

[0217] A potential mechanism by which chronic K+P exerts its behavioral effectsremains to be discovered. The present study focused on examining GFAP and Ki67, respective markers of NSC and neural progenitor cells (NPCs) in the hippocampus. Extensive previous literature has linked adult hippocampal neurogenesis (AHN) to the etiology of depression and antidepressant treatment. Notably, exposure to stress impairs multiple aspects of AHN, and patients with depression exhibit smaller hippocampal volumes when compared with healthy controls. Furthermore, AHN is critically involved in the antidepressant actions of a number of therapeutic compounds, including serotonin-related antidepressants and (7?,5)-ketamine as reviewed previously. In the present study, it was found that P alone, but not K+P, enhances GFAP, but not Ki67, expression specifically in dorsal CAI. These findings suggest that K+P exerts distinct neurobiological effects in comparison to P, and that K+P does not exert its effects by enhancing cell proliferation in the hippocampus. Without being bound to any particular theory, it is believed that chronic K+P can exert its behavioral effects by altering the balance of excitatory / inhibitory (E / I) signaling in the brain or inhibition of glycogen synthase kinase-3p (GSK-3 ).

[0218] It is believed that NMD AR antagonists and 5-HT4R agonists increase synaptic plasticity. An antidepressant dose of K rescues stress-induced dendritic spinogenesis in the mPFC and restores coordinated cell ensemble activity, contributing to a reduction in depression-related behaviors. In patients, K increases connectivity in the default mode network and normalizes brain function during tests of emotional valence. 5-HT4R agonists is suggested to increase spinogenesis and markers of neuroplasticity in the HPC. Clinically, P has been shown in two different studies to enhance memory encoding and recall in healthy volunteers. As disclosed herein, pharmaceutical antidepressant treatment can open a window of significantly enhanced neuroplasticity in the brain. By targeting two different receptors significantly involved in mediating plastic mechanisms of neural connectivity in the brain, combined K + P may increase neuroplasticity in the brain to exert its therapeutic effects.

[0219] In summary, the present study reports that chronic injection and intranasal administration of K+P reverses a variety of stress-induced impairments in behavior in both sexes. This combinatorial drug treatment can also prevent relapse of a depressive episode, suggesting that it can also have benefits for recurrent depression. Overall, the present study shows the benefits of leveraging adjunctive pharmacological treatment to enhance the efficacy of treatment for stress-related psychiatric disorders.

[0220] In at least some of the previously described embodiments, one or more elements used in an embodiment can interchangeably be used in another embodiment unless such a replacement is not technically feasible. It will be appreciated by those skilled in the art thatvarious other omissions, additions and modifications may be made to the methods and structures described above without departing from the scope of the claimed subject matter. All such modifications and changes are intended to fall within the scope of the subject matter, as defined by the appended claims.

[0221] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations may be expressly set forth herein for sake of clarity. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Any reference to “or” herein is intended to encompass “and / or” unless otherwise stated.

[0222] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g, “a” and / or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g, the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “ a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such aconstruction is intended in the sense one having skill in the art would understand the convention (e.g., “ a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms.

[0223] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0224] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like include the number recited and refer to ranges which can be subsequently broken down into sub-ranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 articles refers to groups having 1, 2, or 3 articles. Similarly, a group having 1-5 articles refers to groups having 1, 2, 3, 4, or 5 articles, and so forth.

[0225] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

WHAT IS CLAIMED IS:

1. A method of preventing a relapse of a stress-induced behavior or disorder in a subject, comprising:administering to the subject an effective amount of (1) a serotonin 4 receptor (5- HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and an effective amount of (2) an N-methyl-D-aspartate receptor (NMDAR) antagonist, a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the stress-induced behavior in the subject.

2. The method of claim 1, wherein the stress-induced behavior or disorder comprises fear, behavioral despair, perseverative behaviors, depression or depression-like behavior, and / or anxiety-like behavior.

3. A method of preventing a relapse of a depression or depression-like behavior or disorder in a subject, comprising:administering to the subject an effective amount of a composition comprising (1) a serotonin 4 receptor (5-HT4R) agonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, and (2) an N-methyl-D-aspartate receptor (NMDAR) antagonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof, thereby preventing the relapse of the depression or depression-like behavior or disorder in the subject.

4. The method of claim 3, wherein the depression or depression-like behavior or disorder is stress-induced.

5. The method of claim 3, wherein the depression or depression-like behavior or disorder is not stress-induced.

6. The method of any one of claims 1-5, wherein the NMDAR antagonist or a pharmaceutically acceptable salt, analog, derivative, or metabolite thereof is ketamine or an analog, a derivative or a metabolite thereof.

7. The method of claim 6, wherein the ketamine or analog, derivative or metabolite thereof is selected from the group consisting of: (A)-ketamine, CS')-ketamine, (A,5)-ketamine, hydroxyketamines, dehydronorketamine, (A,5)-norketamine, (2 / ?,6 / ?)-hydroxynorketamine ((2A,6A)-HNK), and (25,65)-hydroxynorketamine ((25,65)-HNK), (2A,6A;25,65)-HNK, and a combination thereof.

8. The method of claim 6, wherein the ketamine or an analog, a derivative or a metabolite is selected from the group consisting of: norketamine, hydroxyketamines, dehydronorketamine, hydroxynorketamine, and a combination thereof.

9. The method of any one of claims 1-8, wherein the NMDAR antagonist is (R,S)~ketamine.

10. The method of any one of claims 1-8, wherein the NMD AR antagonist is (2R, 6R)~ HNK.

11. The method of any one of claims 1-10, wherein the 5-HT4R agonist comprises 1-(4-amino-5-chloro-2-methoxyphenyl)-3-[l(n-butyl)-4-piperidinyl]-l-propanone HC1 (RS-67,333), 4-amino-5-chloro-2,3-dihydro-N-[l-3-methoxypropyl)-4-piperidinyl]-7-benzofuran carboxamide mono hydrochloride (prucalopride), 4-[4-[4-Tetrahydrofuran-3-yloxy)-benzo[d] isoxazol-3-yloxymethyl]-piperidin-l-yhnethyl]-tetrahydropyran-4-ol (PF-04995274), or a combination thereof; and optionally wherein the 5-HT4R agonist is prucalopride.

12. The method of any one of claims 1-11, wherein the 5-HT4R agonist is administered once, twice, three times, four times, five times, six times, or seven times a week.

13. The method of any one of claims 1-12, wherein the NMDAR antagonist is administered once, twice, three times, four times, five times, six times, or seven times a week.

14. The method of any one of claims 1-13, wherein the 5-HT4R agonist is administered at a concentration ranging from about 0.01 mg / kg to about 40 mg / kg of body weight of the subject, optionally, from about 0.01 mg / kg to about 2 mg / kg of body weight of the subject.

15. The method of any one of claims 1-14, wherein the NMDAR antagonist is administered at a concentration ranging from about 0.01 mg / kg to about 40 mg / kg of body weight of the subject, optionally, from about 0.5 mg / kg to about 5 mg / kg of body weight of the subject.

16. The method of any one of claims 1-15, wherein the administration is oral administration, intravenous administration, intranasal administration or an administration via an injection to the subject.

17. The method of any one of claims 1-16, wherein the administration to the subject is intranasal.

18. The method of any one of claims 1-17, wherein (1) the serotonin 4 receptor (5-HT4R) agonist or the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and (2) theN-methyl-D-aspartate receptor (NMDAR) antagonist, the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof are administered sequentially or concurrently.

19. The method of any one of claims 1-17, wherein (1) the serotonin 4 receptor (5-HT4R) agonist or the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof; and (2) theN-methyl-D-aspartate receptor (NMDAR) antagonist, the pharmaceutically acceptable salt, analog, derivative, or metabolite thereof are administrated in a single composition or in two separate compositions.

20. The method of any one of claims 1-19, wherein the administration to the subject is performed prior to a stressor; optionally wherein the administration to the subject is performedabout 48 hours to about 3 weeks prior to a stressor; and further optionally wherein the administration to the subject is performed about 72 hours to about 2 weeks prior to a stressor.

21. The method of any one of claims 1-20, wherein the administration to the subject is performed about 1 week prior to a stressor.

22. The method of any one of claims 1-21, wherein the administration to the subject is performed once prior to a stressor.

23. The method of any one of claims 1-17, wherein the administration to the subject is performed after a stressor; optionally wherein the administration to the subject is performed about 48 hours to about 3 weeks after a stressor; and further optionally wherein the administration to the subject is performed about 72 hours to about 2 weeks after a stressor.

24. The method of claim 23, wherein the administration to the subject is performed about 1 hour to about 1 day after a stressor.

25. The method of any one of claims 23-24, wherein the administration to the subject is performed once after a stressor.

26. The method of any one of claims 1-25, wherein the administration to the subject is performed at least once before a stressor and then after a stressor.

27. The method of any one of claims 1-26, wherein the subject had been or is diagnosed as having a stress-induced affective disorder or stress-induced psychopathology, and optionally wherein the stress-induced affective disorder is post-traumatic stress disorder (PTSD) or major depressive disorder (MDD).

28. The method of claim 27, wherein the stress-induced affective disorder is selected from the group consisting of: depressive-like behavior and associated affective disorders; anhedonic behavior and associated affective disorders; anxiety and associated affective disorders; cognitive impairments and deficits and associated disorders; stress-induced fear; and combinations thereof.

29. The method of any one of claims 27-28, wherein the stress-induced affective disorder comprise depressive-like behavior.

30. The method of any one of claims 27-29, wherein the subject has recovered from the stress-induced affective disorder or stress-induced psychopathology and is considered at risk of relapse.

31. The method of any one of claims 27-30, wherein the subject is in remission from the stress-induced affective disorder or stress-induced psychopathology.

32. The method of claim 31, wherein the subject has been treated with the 5-HT4R agonist alone, with the NMD AR antagonist alone, or with a combination of the 5-HT4R agonist and the NMD AR antagonist prior to the remission.

33. The method of any one of claims 1-32, wherein the subject is in remission phase.

34. The method of claim 33, wherein the subject was in response to a therapy conducted prior to the remission phase.

35. The method of claim 34, wherein the response is complete response or partial response.

36. The method of claim 34, wherein the therapy conducted prior to the remission phase comprises the 5-HT4R agonist alone, the NMD AR antagonist alone, or a combination of the 5-HT4R agonist and the NMD AR antagonist.

37. The method of any one of claims 1-36, wherein the method prevents the relapse of a depressive episode even after discontinuing administration.

38. The method of any one of claims 1-37, wherein the administration does not affect the weight of the subject.

39. The method of any one of claims 1-38, wherein the subject is a mammal, optionally a human.

40. The method of claim 39, wherein the human is female.

41. The method of any one of claims 1-40, further comprising administering an effective amount of an anti-depressant, an anxiolytic, or combinations thereof.

42. The method of any one of claims 1-41, comprising administering an effective amount of a selective serotonin reuptake inhibitor (SSRI), or a pharmaceutically acceptable salt or derivative thereof.

43. The method of any one of claims 1-42, comprising administering an effective amount of fluoxetine, paroxetine, sertraline, lithium, riluzole, prazosin, lamotrigine, ifenprodil, or combinations thereof.

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