Comparative efficacy of alprazolam, imipramine, and placebo administered once a day in treating depressed patients.

Ninety-eight outpatients with major depressive disorder were treated with alprazolam, imipramine, or placebo in a 6-week, double-blind study. Average doses were 3.67 mg of alprazolam and 167 mg of imipramine, given at bedtime. Fifty percent of patients taking alprazolam, 38.2% taking imipramine, and 17.7% receiving placebo improved their HAM-D scores by more than 50%. Eight patients on imipramine, 6 on alprazolam, and 1 on placebo dropped out because of side effects. The most common side effects for imipramine were tachycardia, constipation, light-headedness, and sedation; common side effects of alprazolam were light-headedness, sedation, and unsteadiness.