Clinical characterization of mixed manic features in depressed adolescents without bipolar disorder

Depressed adolescents with co-occurring manic symptoms (mixed features) face an elevated risk for poorer treatment outcomes and suicide. We aimed to characterize mixed manic features in non-bipolar depressed adolescents and investigate their associations with the clinical presentation of depression.

The sample included 178 adolescents (mean age: 15.2 ± 1.7, 66% female), including 140 with moderate-to-severe depression (with/without co-occurring manic symptoms) and 38 without psychiatric diagnoses. Adolescents and parents completed semi-structured interviews, Depression Rating Scale (DRS), Mania Rating Scale (MRS), and questionnaires assessing non-mood psychopathology. Factor analyses were used to characterize adolescents based on clinical features and mood symptoms.

Among the depressed adolescents, 73 (52.1%) had no mixed features, 29 (20.7%) met full DSM-5 mixed manic features criteria, and 38 (27.1%) met most DSM-5-mixed features criteria plus either distractibility and/or mood lability ("broad-mixed" presentation). Adolescents with DSM- and broad-mixed symptoms did not differ on depressive factor scores (DRS, ds = 0.19-0.42), and differences in manic symptoms were primarily driven by elation/energy symptoms (MRS, AUC = 0.97, d = 2.55). Both mixed subgroups differed from the non-mixed subgroup by higher depressive symptoms (neurovegetative, suicidality, and affective/cognitive; DRS, AUC > 0.63) and manic symptoms (elation/energy, mood lability/impulsivity, cognitive overload/hyperactivity; MRS, AUC = 0.77-0.84).

Cross-sectional design and a referred sample.

This study supports the clinical relevance of mixed features in adolescent depression and suggests that a broader, dimensional assessment of manic symptoms, extending beyond DSM definitions, may improve identification of adolescents at risk for significant functional impairment and suicidal behavior. These cross-sectional findings warrant confirmation in longitudinal studies.