The present application relates to compositions for use in a method of treating and / or preventing mental and behavioral disorders and / or improving mental health and cognitive functions in a subject, comprising:a) Docosahexaenoic acid (DHA) and / or the pharmaceutically acceptable derivatives and / or precursors thereof;b) Eicosapentaenoic acid (EPA) and / or the pharmaceutically acceptable derivatives and / or precursors thereof;c) γ-linolenic acid (GLA) and / or the pharmaceutically acceptable derivatives and / or precursors thereof; andat least a psychostimulant compound selected among methylphenidate HCl, atomoxetine, amphetamine, gamma-hydroxybutyrate, dextroamphetamine, sibutramine, methylenedioxymethamphetamine, and / or an anxiolytic compound selected among fluoxatine, sertraline, paroxetine, fluoroxamine, citralopram, venlafaxine, bupropion, nefazodone, and mirtazapine.The present application also relates to the method of treating and / or preventing mental and behavioral disorders and / or improving mental health and cognitive functions in a subject, comprising administering an effective amount of a composition comprising:a) Docosahexaenoic acid (DHA) and / or the pharmaceutically acceptable derivatives and / or precursors thereof;b) Eicosapentaenoic acid (EPA) and / or the pharmaceutically acceptable derivatives and / or precursors thereof;c) γ-linolenic acid (GLA) and / or the pharmaceutically acceptable derivatives and / or precursors thereof; andat least a psychostimulant compound selected among methylphenidate HCl, atomoxetine, amphetamine, gamma-hydroxybutyrate, dextroamphetamine, sibutramine, methylenedioxymethamphetamine, and / or an anxiolytic compound selected among fluoxatine, sertraline, paroxetine, fluoroxamine, citralopram, venlafaxine, bupropion, nefazodone, and mirtazapine.