The present invention is concerned with 
deuterium-enriched sulfonamides of formula 1, their pharmaceutically acceptable salts and methods of use thereof for the treatment of 
anxiety disorders including, General 
Anxiety Disorder (GAD), 
Panic Disorder (PD), Post-Traumatic Stress Disorder (PTSD), Social Phobia (SP), Health 
Anxiety (Hypochondriasis), depression, major depressive disorders, unipolar depression, bipolar I depression disorder, bipolar II depression disorder, treatment-resistant depression, single episodic and recurrent major depressive disorders, depression in the medically ill, 
attention deficit hyperactivity disorder (ADHD), 
attention deficit disorder (ADD), Obsessive-Compulsive Disorder (OCD), Obsessive-Compulsive Personality Disorder (OCPD), 
Autism Spectrum Disorder (ASD), 
schizophrenia, 
psychosis, 
epilepsy, seizures, hot flashes due to 
menopause, age-related 
macular degeneration (AMD), premature ejaculation, 
male erectile dysfunction, 
sexual dysfunction, 
obesity, 
eating disorders, 
bulimia nervosa, 
anorexia nervosa, 
angina, 
migraine, pain, 
nociception, sleep disorders, 
insomnia, 
fibromyalgia, 
alcohol withdrawal, 
autism, Rett'
s syndrome, cyclothymic disorder, neural injury, neurodegenerative diseases, Parkinson's 
disease, Parkinson's 
disease psychosis, Huntington 
disease, Alzheimer's disease, 
frontotemporal dementia, 
cognitive impairment associated with age-related 
dementia, Alzheimer's disease, 
schizophrenia, 
psychosis, depression, pain or discomfort associated with 
surgery and pain or discomfort associated with 
medical illness.