Co-occurring mental health problems and peer functioning among youth with attention-deficit/hyperactivity disorder: a review and recommendations for future research.

It is well established that children and adolescents with attention-deficit/hyperactivity disorder (ADHD) frequently experience co-occurring mental health problems in addition to difficulties in their peer relationships. Although substantial research has focused on the extent to which peer functioning contributes to subsequent co-occurring mental health problems, much less research has considered how co-occurring mental health problems affect peer functioning domains. Therefore, the purpose of this review is to examine the effect of co-occurring mental health problems on the peer functioning of youth with ADHD. The impact of co-occurring externalizing (i.e., oppositional defiant disorder, conduct disorder) and internalizing (i.e., anxiety, depression) symptoms are reviewed, with a focus on whether these co-occurring symptoms exacerbate, attenuate, or have no effect across peer domains of social skills/competence, peer status, and friendship among youth with ADHD. Drawing from a developmental psychopathology framework, this review then draws attention to relevant causal processes and developmental cascades (including social-cognitive, affective, and family and parenting factors) in offering promising avenues for future work.