Gepirone treatment of atypical depression: preliminary evidence of serotonergic involvement.

This is a report of a controlled trial of gepirone, a 5-hydroxytryptamine (5-HT1A) partial agonist azapirone related to buspirone, in the treatment of atypical depression. The azapirones are of particular interest because their highly selective actions on the serotonergic system may possibly make them useful pharmacologic probes and potentially selective therapeutic agents. Sixty outpatients meeting Columbia criteria for definite or probable atypical depression were enrolled in a double-blind, randomized, placebo-controlled, 8-week clinical trial at a single site. The dosage schedule was fixed flexible, with 10-mg capsules given on a thrice-daily schedule, with doses of up to 120 mg daily. The response rate at 8 weeks for the intention-to-treat sample analyzed with the last observation carried forward was 62% (18 of 29 patients) for gepirone and 20% (6 of 30 patients) for placebo (chi 2 = 9.1; df = 1; p < 0.001). Robust and consistent drug-placebo differences are seen across virtually all rating scales post-treatment. The effect of gepirone was consistent across the levels of concomitant variables, including duration of episode and presence of dysthymia or panic. Gepirone is a novel antidepressant that holds promise for the treatment of atypical depression and that may be of heuristic value because of its relatively specific actions on the serotonergic system.