Objectives

To identify mood symptoms that distinguishes bipolar disorder (BP) depression versus unipolar depression in youth during an acute depressive episode.

Methods

Youth with BP (N = 30) were compared with youth with unipolar depression (N = 59) during an acute depressive episode using the depression and mania items derived from the Schedule for Affective Disorders and Schizophrenia for Children (K-SADS)-Present Version. The results were adjusted for multiple comparisons, and any significant between-group differences in demographic, nonmood comorbid disorders, and psychiatric family history.

Results

In comparison with unipolar depressed youth, BP depressed youth had significantly higher scores in several depressive symptoms and all subsyndromal manic symptoms, with the exception of increased goal-directed activity. Among the depressive symptoms, higher ratings of nonsuicidal physical self-injurious acts and mood reactivity, and lower ratings of aches/pains, were the symptoms that best discriminated BP from unipolar depressed youth. Subsyndromal manic symptoms, particularly motor hyperactivity, distractibility, and pressured speech, were higher in BP depressed youth and discriminated BP depressed from unipolar depressed youth.

Conclusions

The results of this study suggest that it is possible to differentiate BP depression from unipolar depression based on depressive symptoms, and in particular subsyndromal manic symptoms. If replicated, these results have important clinical and research implications.