Reviewing the diagnostic validity and utility of mixed depression (depressive mixed states)

Objective. -To review the diagnostic validity and utility of mixed depression, i.e. co-occurrence of depression and manic/hypomanic symptoms. Methods. -PubMed search of all English-language papers published between January 1966 and December 2006 using and cross-listing key words: bipolar disorder, mixed states, criteria, utility, validation, gender, temperament, depression-mixed states, mixed depression, depressive mixed state/s, dysphoric hypomania, mixed hypomania, mixed/dysphoric mania, agitated depression, anxiety disorders, neuroimaging, pathophysiology, and genetics. A manual review of paper reference lists was also conducted. Results. -By classic diagnostic validators, the diagnostic validity of categorically-defined mixed depression (i.e. at least 2-3 manic/hypomanic symptoms) is mainly supported by family history (the current strongest diagnostic validator). Its diagnostic utility is supported by treatment response (negative effects of antidepressants). A dimensionally-defined mixed depression is instead supported by a non-bi-modal distribution of its intradepression manic/hypomanic symptoms. Discussion. -Categorically-defined mixed depression may have some diagnostic validity (family history is the current strongest validator). Its diagnostic utility seems supported by treatment response. (C) 2007 Elsevier Masson SAS. All rights reserved.