A double-blind, placebo- and amitriptyline-controlled comparison study was performed to evaluate the antidepressant efficacy of sertraline, a specific serotonin uptake inhibitor. Patients with DSM-III-defined major depression randomly received either sertraline (N = 149), amitriptyline (N = 149), or placebo (N = 150) once daily for the 8-week study period. The mean final daily medication dose for the all-patients group was 145 mg and 104 mg for the sertraline- and amitriptyline-treatment groups, respectively. As measured by the Hamilton Rating Scale for Depression and the Clinical Global Impressions Scale, both the sertraline and amitriptyline treatment groups showed a significantly greater improvement from baseline (p less than or equal to .001) than the placebo group. The sertraline group had a higher proportion of gastrointestinal complaints and male sexual dysfunction than either the amitriptyline or the placebo group. The amitriptyline group showed a higher proportion of anticholinergic and sedative side effects and dizziness compared with patients who received either sertraline or placebo.