DO NONDSM CRITERIA ENHANCE THE VALIDITY OF THE DSM-5 MIXED FEATURES SPECIFIER IN DEPRESSED PATIENTS?

Background

During the past 2 decades there has been intense interest in the clinical significance of the concurrence of manic symptoms in depressed patients. DSM-5 introduced a mixed features specifier for both bipolar depression and major depressive disorder. Studies of the DSM-5 mixed features specifier have generally found a low prevalence of mixed depression. The DSM-5 definition requires the presence of 3 or more of the 7 symptoms for the majority of the episode. The most controversial aspect of the DSM-5 mixed features criteria are the symptoms included in the definition. To avoid the double counting of symptoms as indicative of both depression and mania, the DSM-5 definition includes only “opposite polarity” symptoms and thus does not include features of depression such as agitation or distractibility. Several authors have been critical of the DSM criteria set for failing to include those symptoms that traditionally have been viewed as central to mixed states (i.e. agitation, irritability, distractibility). We use the acronym AID to refer to these symptoms. In the present report from the Rhode Island methods to Improve Diagnostic Assessment and Services (MIDAS) project we examined the impact on the prevalence and validity of mixed depression of adding the AID symptoms to the DSM-5 criteria set.

Methods

Four hundred fifty-nine psychiatric patients in a depressive episode were interviewed by a trained diagnostic rater who administered semi-structured interviews including the DSM-5 Mixed Features Specifier Interview (DMSI). The DMSI assesses the 7 DSM-5 criteria of the mixed features specifier (elevated mood, inflated self-esteem, increased talkativeness, thought racing, increased energy or goal directed activity, increased activity with potentially painful consequences, decreased need for sleep) as well as the 3 AID symptoms (agitation, irritability, distractibility).

Results

We added the 3 AID symptoms to the 7 DSM-5 criteria and examined the distribution of number of mixed features and the prevalence of mixed features based on different cutoffs. At the DSM-5 cutoff of 3, the prevalence of mixed features increased from 3.9% to 42.7%. Increasing the cutoff to 4 reduced the prevalence of mixed features by more than 15%, and increasing the cutoff to 5 reduced the prevalence by more than another 15%. Even at a cutoff of 5, the prevalence based on the 7 DSM-5 plus 3 AID symptoms was > the prevalence based on the DSM-5 criteria (cutoff of 3 of 7 features) (6.5% vs. 3.9%). Patients who met the mixed features specifier based on the DSM-5 criteria were more likely to be diagnosed with bipolar disorder. Amongst the patients with major depressive disorder, meeting the DSM-5 mixed features criteria was associated with an increased family history of bipolar disorder. We added the 3 AID symptoms to the 7 DSM-5 criteria and focused on the patients who newly met the mixed features criteria (and did not meet the DSM-5 definition). In these patients, there was no association between the mixed features specifier and a diagnosis of bipolar disorder or a family history of bipolar disorder.

Conclusions

The results of the present study do not support adding the symptoms of agitation, irritability, and distractibility to the DSM-5 definition of the mixed features specifier.