Clinical implications of pervasive manic symptoms in children.

BACKGROUND Prior investigations of cross-informant agreement among parents, teachers, and clinicians about externalizing and internalizing problems have not directly addressed agreement about manic symptoms. METHODS We identified three groups from a large cohort of youths, aged 8-12 years, treated on an inpatient unit. All 108 participants met criteria for an externalizing disorder, based on a semi-structured diagnostic interview. Of these, 49 did not have manic symptoms endorsed by either the parent or a teacher; 34 had manic symptoms reported by the parent only, and 25 had pervasive manic symptoms (i.e., corroborated by both sources). RESULTS The "corroborated mania" group consistently showed the most disruptive behavior on the inpatient unit, the worst behavior problems on multiple scales, and the longest admission durations. The "parent-only" group scored in the midrange on all of these measures, with group differences typically representing small to medium effect sizes. The "externalizing only" group consistently scored lowest on all dependent measures, with the differences representing large to extremely large effects when compared with the corroborated mania group and medium effects as compared with the parent-only group. CONCLUSIONS Youths for whom multiple informants report manic symptoms appear likely to have more severe symptom presentation and more complicated, refractory courses than do youths without manic symptoms.