These data suggest that the presentation of juvenile BP-I is a cyclic and valid clinical condition with manifestations on a continuum with the later-onset forms of this illness.

Objective To examine the proposed disruptive mood dysregulation disorder (DMDD) diagnosis in a child psychiatric outpatient population. Evaluation of DMDD included 4 domains: clinical phenomenology, delimitation from other diagnoses, longitudinal stability, and association with parental psychiatric disorders. Method Data were obtained from 706 children aged 6–12 years who participated in the Longitudinal Assessment of Manic Symptoms (LAMS) study (sample was accrued from November 2005 to November 2008). DSM-IV criteria were used, and assessments, which included diagnostic, symptomatic, and functional measures, were performed at intake and at 12 and 24 months of follow-up. For the current post hoc analyses, a retrospective diagnosis of DMDD was constructed using items from the K-SADS-PL-W, a version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children, which resulted in criteria closely matching the proposed DSM-5 criteria for DMDD. Results At intake, 26% of participants met the operational DMDD criteria. DMDD+ vs DMDD– participants had higher rates of oppositional defiant disorder (relative risk [RR] = 3.9, P < .0001) and conduct disorder (RR = 4.5, P < .0001). On multivariate analysis, DMDD+ participants had higher rates of and more severe symptoms of oppositional defiant disorder (rate and symptom severity P values < .0001) and conduct disorder (rate, P < .0001; symptom severity, P = .01), but did not differ in the rates of mood, anxiety, or attention-deficit/hyperactivity disorders or in severity of inattentive, hyperactive, manic, depressive, or anxiety symptoms. Most of the participants with oppositional defiant disorder (58%) or conduct disorder (61%) met DMDD criteria, but those who were DMDD+ vs DMDD– did not differ in diagnostic comorbidity, symptom severity, or functional impairment. Over 2-year follow-up, 40% of the LAMS sample met DMDD criteria at least once, but 52% of these participants met criteria at only 1 assessment. DMDD was not associated with new onset of mood or anxiety disorders or with parental psychiatric history. Conclusions In this clinical sample, DMDD could not be delimited from oppositional defiant disorder and conduct disorder, had limited diagnostic stability, and was not associated with current, future-onset, or parental history of mood or anxiety disorders. These findings raise concerns about the diagnostic utility of DMDD in clinical populations.

Findings suggest that parents most notice elated mood, high energy, irritability, and rapid changes in mood and energy as the prominent features of juvenile bipolar disorder.