Phenelzine for chronic depression: a study of continuation treatment.

Several controlled studies have demonstrated the efficacy of continuation therapy with tricyclic antidepressants, but little is known about continuation therapy with the monoamine oxidase inhibitors. Moreover, the usefulness of continuation antidepressant therapy in patients with chronic depressive disorders has not been evaluated. This pilot study reports initial results of a double-blind continuation trial of phenelzine or placebo following an initial antidepressant response to phenelzine in 12 patients who met DSM-III criteria for dysthymic disorder. All 7 patients randomized to placebo relapsed, whereas only 1 of the 5 patients who continued to receive phenelzine relapsed. These results suggest that continuation therapy with phenelzine may be useful in maintaining clinical response after acute treatment.