Mixed states are characterized by concurrent manic and depressive symptoms. The concept of a “with mixed features” specifier for major depressive episodes was introduced in DSM-5 and defined by the presence of at least three nonoverlapping opposite-pole symptoms in the context of a syndromal depressive, hypomanic, or manic episode. There has been growing interest in the phenomenology and clinical implications of the opposing mixed state—that is, manic or hypomanic symptoms during a depressive episode. A study published in the American Journal of Psychiatry assessed the prevalence and features of mixed depression among bipolar disorder patients and qualitatively compared a range of diagnostic thresholds for mixed depression.
Visit outcomes of adult outpatients (N=907) with bipolar disorder across 14,310 visits between 1995 and 2002 were analyzed. At each visit, mania and depression symptoms were assessed using the Inventory of Depressive Symptomatology–Clinician-Rated Version (IDS-C) and the Young Mania Rating Scale (YMRS). Patients with an IDS-C score of greater or equal to 15 and a YMRS score between 2 and 12 at the same visit were classified as having mixed depression. The presence of mixed depression was observed in 2,139 visits (14.9% of total) and among 584 patients (64.4% of total). Those classified as having one or more mixed depression visits also had more symptomatic visits and fewer non-depressed visits compared with those with no mixed depression visits.
The authors concluded that among the patient population studied, depressive symptoms were common, and subthreshold hypomania occurred in almost half of all visits with depression. The study revealed that women were more likely than men to experience hypomanic symptoms concurrently with depression across a range of diagnostic criteria for mixed depression. “The presence of mixed depression appears to be a marker of vulnerability to mixed depression features in general and may portend a more symptomatic course of illness over time. The stability of our mixed depression construct across a range of definitions supports the possibility that broader diagnostic criteria for mixed depression may improve sensitivity while preserving clinical meaningfulness.”
Source: American Journal of Psychiatry
Published Online April 15, 2016