Course and outcome of bipolar II disorder: a retrospective study.

To study course and outcome of Bipolar II disorder, 217 major depressive episode (MDE) patients were interviewed with Structured Clinical Interview for DSM-IV. Patients with more than three MDE and patients with fewer MDE were compared. Patients with more than three MDE were 77.8%. Comparisons, controlled for confounding effects of age and illness duration, found that patients with many MDE had significantly lower age at onset and more chronicity. Results support subtyping of Bipolar II in a small good-outcome group, and a large moderate-poor-outcome group.