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: 664–671. © 2012 The Authors. Journal compilation © 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): 1.06–3.83, 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: 0.06–1.05, 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.