Measures of the DSM-5 mixed-features specifier of major depressive disorder

During the past two decades, a number of studies have found that depressed patients frequently have manic symptoms intermixed with depressive symptoms. While the frequency of mixed syndromes are more common in bipolar than in unipolar depressives, mixed states are also common in patients with major depressive disorder. The admixture of symptoms may be evident when depressed patients present for treatment, or they may emerge during ongoing treatment. In some patients, treatment with antidepressant medication might precipitate the emergence of mixed states. It would therefore be useful to systematically inquire into the presence of manic/hypomanic symptoms in depressed patients. We can anticipate that increased attention will likely be given to mixed depression because of changes in the DSM-5. In the present article, I review instruments that have been utilized to assess the presence and severity of manic symptoms and therefore could be potentially used to identify the DSM-5 mixed-features specifier in depressed patients and to evaluate the course and outcome of treatment. In choosing which measure to use, clinicians and researchers should consider whether the measure assesses both depression and mania/hypomania, assesses all or only some of the DSM-5 criteria for the mixed-features specifier, or assesses manic/hypomanic symptoms that are not part of the DSM-5 definition. Feasibility, more so than reliability and validity, will likely determine whether these measures are incorporated into routine clinical practice.