Understanding Co-Occurring ADHD and Anxiety Symptoms within a Developmental Framework: Risk and Protective Factors of Early Temperament and Peer Relations.

Symptoms of ADHD and anxiety often co-occur, yet we are limited in our understanding of which children with ADHD symptoms are more likely to develop anxiety symptoms in adolescence. This longitudinal study examined the role of behavioral inhibition (BI) and peer relationships (i.e., peer support and peer victimization) in relation to childhood ADHD and adolescent anxiety symptoms in a community sample, which was oversampled for reactivity. Data were drawn from a larger longitudinal study (N = 291) examining trajectories of BI. For the current analyses, we used behavioral observations of BI at ages 2 and 3, parent report of their child's ADHD symptoms at age 7, child report of peer support and peer victimization at age 12, and adolescent report of anxiety symptoms at age 15. Using structural equation modeling, results indicated that BI and peer support moderated the relation between ADHD and anxiety symptoms, such that ADHD symptoms predicted later anxiety symptoms only for youth who displayed low BI in toddlerhood and reported experiencing lower levels of peer support in early adolescence. Findings highlight the role of early temperament and peer relationships on the relation between childhood ADHD and adolescent anxiety symptoms, and underscore the importance of evaluating multiple risk factors when examining the development of psychopathology.