Assessing the Irritable and Defiant Dimensions of Youth Oppositional Behavior Using CBCL and YSR Items.

Research suggests that irritability and defiance are distinct dimensions of youth oppositionality that are differentially associated with internalizing and conduct problems, respectively. Because much of this evidence has emerged with limited psychometric evaluation, we conducted the first multi-informant examination of selected Child Behavior Checklist (CBCL) and Youth Self Report (YSR) items for measuring irritability and defiance in a large clinical sample. Clinically referred youths (N = 1,030; ages 6-15; 43% female, 42% ethnic minority) were assessed prior to treatment using multi-informant rating scales and diagnostic interviews. Analyses examined factor structure, invariance, internal consistency, multi-informant patterns, and convergent, discriminant, and criterion validity with internalizing and externalizing problems/disorders. A correlated 2-factor model of irritability (stubborn/sullen/irritable, mood, temper) and defiance (argues, disobeys-home, disobeys-school) fit well for both informants. Adequate measurement invariance and scale consistency was consistently found for parent-report but not youth-report. With both informants, all hypothesized convergent and discriminant validity associations were supported: irritability and defiance with internalizing and conduct scales, respectively. However, hypothesized criterion validity associations were largely found only by parent-report: irritability with anxiety and depressive disorders, defiance with conduct disorder, and both with oppositional defiant disorder. Results consistently supported the reliability and validity of the CBCL irritability and defiance scales, with somewhat less consistent support for the YSR scales. Thus, CBCL items may provide psychometrically sound assessment of irritability and defiance, whereas further research is needed to advance youth-report and multi-informant strategies. Results also provide further support for a two subdimension model of oppositional defiant disorder symptoms that includes irritability and defiance.