Polarity of the first episode, clinical characteristics, and course of manic depressive illness: A systematic retrospective investigation of 320 bipolar I patients

In 320 patients with established bipolar I disorder, we examined the past c ourse on the basis of polarity at onset (depressive, mixed, and manic). Des pite the obvious limitations of retrospective methodology, information on c ourse parameters in a large sample of affective disorders is most practical ly obtained by such methodology. We believe that our systematic interview o f patients and their relatives-as well as the systematic study of their rec ords-minimized potential biases. Depressive onsets were the most common, ac counting for 50%, followed by mixed and manic onsets in about equal proport ion. In general, the polarity of episodes over time reflected polarity at o nset, Those with depressive onset had significantly higher levels of rapid cycling, as well as suicide attempts, but were significantly less likely to develop psychotic symptoms. Mixed onsets, too, had high rates of suicide a ttempts, but differed from depressive onsets in having significantly more c hronicity yet negligible rates of rapid cycling at follow-up evaluation. Be cause cases with depressive onset had received significantly higher rates o f psychopharmacologic treatment, our data are compatible with the hypothesi s that antidepressants may play a role in the induction of rapid cycling. O verall, our data support the existence of distinct longitudinal patterns wi thin bipolar I disorder, which in turn appear correlated with the polarity at onset. In particular, rapid cycling and mixed states emerge as distinct psychopathologic processes. Copyright (C) 2000 by W.B. Saunders Company.