8 Controversies in Bipolar Disorder Addressed

Nassir Ghaemi, MD, MPH; Stephen M. Strakowski, MD


June 30, 2016

Controversy 7: Interpreting the Mixed Modifier

How would you interpret or use the new DSM-5 mixed modifier?

Dr Ghaemi: I think this is a step forward, because it allows the concept of mixed states to apply to MDD, and not just BD. It harkens back to the original notion of mixed states—which had nothing to do with BD, but instead reflected the idea that most mood states of any kind, whether depressive or manic, are not purely one way or the other, but tend to have some mixture of mood symptoms of both kinds.

The problem with the DSM-5 definition is that it was abstract and speculative, rather than based on empirical data. The DSM-5 task force decided, on a priori speculative grounds, to disallow any "overlapping" mood symptoms when diagnosing mixed features. Thus, irritable mood and psychomotor agitation, which are the most common mixed symptoms, are not allowed as diagnostic of mixed features in DSM-5. This would be like saying that in the diagnosis of migraine, pain in the head is not allowed as a diagnostic symptom.

The empirical literature contradicts the DSM-5 opinion—but unfortunately, as with all things DSM-related, the profession is faced with a top-down mandate of a professional organization, even when the scientific literature supports other views. I appreciate the step made by DSM-5, but I support using the mixed concept on the basis of our best scientific data, not the theoretical views of DSM-5.

Dr Strakowski: The struggle with the constantly changing definitions of "mixed states" in DSM-5 and all of its predecessors is an ongoing failure to recognize the roles of diagnostic constructs. Namely, there are three major roles: 1) to guide treatment, because evidence has accumulated that a specific diagnostic construct responds to a specific treatment; 2) to guide prognosis on the basis of the same rationale, so that we can help patients know what to expect; and 3) to guide research, so that two investigators talking about something will define it similarly.

In the case of the DSMs, which are predominantly and widely used as clinical documents, changes in diagnostic constructs should occur rarely and only with evidence suggesting that a change is needed. Unfortunately, the mixed-state definitions in the DSM change so often, with so little evidence that a change is necessary or an improvement, that in the end I don't think we have enough information to tell whether the most recent change improved how we care for people or not and certainly has not added to research. My hope is that the current iteration will stay in place long enough to be tested to see whether it meets any of the roles a diagnostic construct plays.


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