Chronic mood disorders in depressed outpatient--diagnosis and response to pharmacotherapy.

The current study was devised to assess the utility of Research Diagnostic Criteria (RDC) categories used to classify minor mood disorders. Similar categories are to be used in the APA's Diagnostic and Statistical Manual, 3rd edition. The patient sample consisted of 64 consecutive admissions to a double-blind trial of amitriptyline, perphenazine and the combination as treatment for depression. Patients who met RDC for a current episode of major depressive disorder were given 4 weeks of pharmacotherapy as treatment. Chronic mood disorders were also assessed using RDC criteria. This evaluation revealed that only 34% met criteria for an episode of major depressive disorder alone, while 36% met criteria for intermittent depressive disorder, 14% for cyclothymic personality and 16% for labile personality in addition to being in a current major depressive episode. These 4 diagnostic subgroups were compared on demographic characteristics, childhood history, psychiatric history, presenting patterns of symptoms and social functioning, and response to treatment. Differences were noted in the subgroups in presenting symptom levels and residual impairment. However, there was no differential response to a brief course of antidepressant pharmacotherapy in patients with and without chronic minor mood disorders. Most patients showed an improvement during the brief course of treatment. Thus, the presence of a chronic minor mood disorder does not appear to be contraindication for use of medication in patients who also are currently experiencing a major depressive episode.