title: Duration of antidepressant trials: clinical and research implications.
abstract: The objective of our study was to demonstrate that additional antidepressant benefit occurs between weeks 4 and 6 in adult outpatients, even when dose is not increased. Response between weeks 4 and 6 was studied among depressed outpatients randomly assigned to imipramine, phenelzine, or placebo under double-blind conditions. Patients were selected for analysis only if they did not have a dose increase after the start of the fourth week of treatment (day 22). Eighty-eight patients met this condition. Conditional probability analysis was performed. Nonresponders to 4 weeks (28 days) of treatment had a significantly greater likelihood of responding by week 6 if they were on phenelzine rather than placebo. The same is probably true for patients on imipramine. In research and clinical care, 4 weeks is too short a trial of phenelzine to conclude a lack of efficacy. Four weeks is probably also too short a trial of imipramine.
authors.affiliation: Department of Therapeutics, New York State Psychiatric Institute, New York 10032.
authors.forename: S J
authors.initials: SJ
authors.lastname: Donovan
authors.forename: F M
authors.initials: FM
authors.lastname: Quitkin
authors.forename: J W
authors.initials: JW
authors.lastname: Stewart
authors.forename: K
authors.initials: K
authors.lastname: Ocepek-Welikson
authors.forename: W
authors.initials: W
authors.lastname: Harrison
authors.forename: P J
authors.initials: PJ
authors.lastname: McGrath
authors.forename: E V
authors.initials: EV
authors.lastname: Nunes
authors.forename: S
authors.initials: S
authors.lastname: Wager
authors.forename: E
authors.initials: E
authors.lastname: Tricamo
mesh_terms: D000328:Adult; D003866:Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007099:Imipramine / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D010555:Personality Inventory; D010624:Phenelzine / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D010624:Phenelzine; D007099:Imipramine