- Current or history of treatment with medications that may cause significant weight gain within 3 months prior to screening, including systemic corticosteroids (except for a short course of treatment, i.e. 7−10 days), tricyclic antidepressants, atypical antipsychotic and mood stabilizers (e.g. imipramine, amitriptyline, mirtazapine, paroxetine, phenelzine, chlorpromazine, thioridazine, clozapine, olanzapine, valproic acid and its derivatives, and lithium);