Bipolar mixed states: an international society for bipolar disorders task force report of symptom structure, course of illness, and diagnosis.

ObjectiveEpisodes of bipolar disorder are defined as depressive or manic, but depressive and manic symptoms can combine in the same episode. Coexistence or rapid alternation of depressive and manic symptoms in the same episode may indicate a more severe form of bipolar disorder and may pose diagnostic and treatment challenges. However, definitions of mixed states, especially those with prominent depression, are not well established.MethodThe authors performed literature searches for bipolar disorder, multivariate analyses, and the appearance of the terms “mixed” in any field; references selected from the articles found after the search were combined after a series of conferences among the authors.ResultsThe authors reviewed the evolution of the concept of mixed states and examined the symptom structure of mixed states studied as predominantly manic, predominantly depressive, and across both manic and depressive episodes, showing essentially parallel structures of mixed states based on manic or depressive ...