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

To review the DSM-5 proposed criteria for mixed depression in light of robust and consistent historical and scientific evidence.

An extensive historical search, a systematic review of the papers used by DSM-5 as reference papers, and a PubMed search were performed.

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.

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.