Course of illness following prospectively observed mania or hypomania in individuals presenting with unipolar depression

Fiedorowicz JG, Endicott J, Solomon DA, Keller MB, Coryell WH. Course of illness following prospectively observed mania or hypomania in individuals presenting with unipolar depression. Bipolar Disord 2012: 14: 664671. (c) 2012 The Authors. Journal compilation (c) 2012 John Wiley & Sons A/S. Objectives: In a well-defined sample, we sought to determine which clinical variables, some of potential nosological relevance, influence subsequent course following prospectively observed initial episodes of hypomania or mania (H/M). Methods: We identified 108 individuals in the National Institute of Mental Health Collaborative Depression Study diagnosed with unipolar major depression at intake who subsequently developed H/M. We assessed time to repeat H/M based on whether one had been started on an antidepressant or electroconvulsive therapy within eight weeks of developing H/M, had longer episodes, or had a family history of bipolar disorder. Results: Modeling age of onset, treatment-associated H/M, family history of bipolar disorder, duration of index H/M episode, and psychosis in Cox regression analysis, family history of bipolar disorder (n = 21) was strongly associated with repeat episodes of H/M [hazard ratio (HR) = 2.01, 95% confidence interval (CI): 1.063.83, p = 0.03]. Those with treatment-associated episodes (n = 12) were less likely to experience subsequent episodes of H/M, although this was not significant in the multivariate model (HR = 0.25, 95% CI: 0.061.05, p = 0.06). These individuals also had a later age of onset for affective illness and were more likely to be depressed. Duration of illness with a temporal resolution of one week, psychosis, and age of onset were not associated with time to repeat H/M episode. Conclusions: A family history of bipolar disorder influences the course of illness, even after an initial H/M episode. In this select sample, treatment-associated H/M did not appear to convey the same risk for a course of illness characterized by recurrent H/M episodes.