How Many Criteria Should Be Required to Define 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. One approach toward increasing the sensitivity of the DSM-5 mixed features criteria is to lower the classification threshold. In the present study, we examine the impact of lowering the DSM-5 diagnostic threshold from 3 to 2 criteria on the prevalence and validity of the DSM-5 mixed features specifier for depression.

Methods

Four hundred fifty-nine psychiatric patients in a depressive episode were interviewed by a trained diagnostic rater who administered semistructured interviews including the DSM-5 Mixed Features Specifier Interview. The patients were rated on clinician rating scales of depression, anxiety, and irritability and measures of psychosocial functioning, suicidality, and family history of bipolar disorder.

Results

When the DSM-5 diagnostic threshold was lowered from 3 to 2 symptoms, the prevalence of mixed features based on the DSM-5 majority of episode time frame tripled from 3.9% to 13.1% (n=60). Based on a past week time frame, the prevalence of mixed features more than doubled from 9.4% to 22.9% (n=105) upon lowering the threshold from 3 to 2 criteria. However, there was no difference between the patients with 2 mixed features and patients with 0 or 1 mixed features on family history of bipolar disorder, psychosocial impairment, presence of comorbid disorders, age of onset, or history of suicide attempts or psychiatric hospitalization.

Conclusions

The results of the present study do not support lowering the DSM-5-TR diagnostic threshold for the mixed features specifier in depressed patients from 3 to 2 criteria.