DSM-5 criteria for depression with mixed features: a farewell to mixed depression.

OBJECTIVE: To review the DSM-5 proposed criteria for mixed depression in light of robust and consistent historical and scientific evidence. METHOD: An extensive historical search, a systematic review of the papers used by DSM-5 as reference papers, and a PubMed search were performed. RESULTS: As Hippocrates, depressive mixed states have been described as conditions of intense psychic suffering, consisting of depressed mood, inner tension, restlessness, and aimless psychomotor agitation. In DSM-5, new criteria are proposed for a mixed features specifier, as part of depression either in major depressive disorder (MDD) or bipolar disorder. Those criteria require, as diagnostically specific, manic/hypomanic symptoms that are the least common kinds of symptoms that actually arise in depressive mixed states. The DSM-5 proposal is based, almost entirely, on a speculative wish to avoid 'overlapping' manic and depressive symptoms. Mixed states are, in fact, nothing but overlapping manic and depressive symptoms. CONCLUSION: In this article, we review the psychopathology and research on mixed depressive states, and try to demonstrate that the DSM-5 proposal has weak scientific basis and does not identify a large number of mixed depressive states. This may be harmful because of the different treatment required by these conditions.