Association of Irritability with Restricted, Repetitive Behaviors and Social Communication Challenges in Autistic Youth.

Although affective irritability is a common and concerning problem for autistic youth, limited research has examined relations among core autism characteristics and irritability. Therefore, this study investigated potential associations among types of restricted/repetitive behaviors (RRBs) and social communication challenges and irritability in autistic children and adolescents. Participants were 107 autistic youth recruited from a university-based autism clinical research program. Two hierarchical multiple regressions were conducted with Affective Reactivity Index as the dependent variable. Covariates were entered at step 1, followed by the independent variables of interest at step 2. For the first model, independent variables of interest were Repetitive Behavior Scale-Revised subscales: stereotyped behavior, self-injurious behavior, compulsive behavior, ritualistic behavior, sameness behavior, and restricted behavior. For the second model, independent variables of interest were Social Responsiveness Scale, Second Edition subscales: social awareness, social cognitive, social communication, and social motivation. Irritability was significantly associated with several categories of RRBs (i.e., insistence on sameness, stereotypic behavior, and restricted interests/activities). Nonetheless, irritability was not associated with categories of social communication and interaction challenges in autistic youth. Results from this study indicated differing associations between core autism characteristics and affective irritability. Findings highlight the importance of differentiating types of restricted, repetitive behaviors and social communication and interaction challenges in conceptualizing mental health concerns in autistic youth.