Efficacy of desipramine in depressed outpatients. Response according to research diagnosis criteria diagnoses and severity of illness.

The efficacy of desipramine for mild depression was tested in a double-blind, placebo-controlled study of outpatients with scores below 19 on the Hamilton Rating Scale for Depression (HAM-D). Of 103 such patients, 23 dropped out and 16 improved during a ten-day placebo period. Among 64 patients completing the randomized portion of the study, significantly more improved with desipramine that with placebo. The Research Diagnostic Criteria (RDC) category of major depressive disorder largely accounted for the drug-placebo response difference found for the entire sample. Patients with intermittent depressive disorder improved significantly less frequently with desipramine than patients with major depressive disorder. Independent of RDC diagnosis, severity of illness correlated with outcome. Thus, patients with pretreatment HAM-D scores at or above the median demonstrated significant drug effect, while patients with lower pretreatment HAM-D scores did not.