Bipolar disorders in DSM-5: Changes and implications for clinical research

The focus of this chapter is the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) conceptualization of bipolar disorder and the associated implications for DSM-5 diagnostic and clinical research. In comparison to earlier DSM iterations, there are several fundamental revisions in DSM-5 criteria and nomenclature. First, the diagnosis has moved from the inclusive categories of “Mood Disorders” in DSM-IV/IV TR and “Affective Disorders” in DSM-III (each of which included all depressive and bipolar disorders) to its own stand-alone category, Bipolar and related disorders - distinct from depressive disorders. Second, the fundamental Criterion A for the diagnosis of a manic or hypomanic episode now requires increased energy or activity to be present with elevated, expansive, or irritable mood. Third, mixed episodes - the presence of a concurrent manic and major depressive episode - has been removed and replaced with a “mixed specifier” feature, allowing “mixed” to be used when subsyndromal depressive or manic/hypomanic symptoms are present in the alternate syndromal episodes. Fourth, antidepressant or other treatment-induced full-syndromal mania or hypomania is no longer diagnosed if symptoms persist and meet episode criteria beyond the physiological effects of the drug, essentially allowing all people whose manic symptoms appear during antidepressant treatment and continue despite stopping the antidepressant to be formally diagnosed with bipolar I or II disorder. Finally, an “anxious distress” modifier has been added as anxious symptoms are commonly present in bipolar disorder but are not accounted for in its diagnostic criteria. Short-duration hypomania with depressive episodes was considered as a diagnostic entity and ultimately included in Section III as a condition for further study; it should also be noted that the Not Otherwise Specified (NOS) category is now replaced throughout DSM-5 by Other Specified and an Unspecified category. The Other Specified is intended to identify four distinct bipolar spectrum conditions, including short-duration hypomania with depression. DSM-5 is intended to bridge the gap between the evidence collected in the Research Domain Criteria (RDoC) context - “new ways of classifying mental disorders based on behavioral dimensions and neurobiological measures” - and practice. The National Institute of Mental Health (NIMH)‘s RDoC sets up a framework for the understanding of domains of brain functioning and impairment independent of the current diagnostic structure. It is hoped and anticipated that such work will allow for a better understanding of psychopathology across clinical entities (Insel et al., 2010).