Autonomic reactivity in clinically referred children attention-deficit/hyperactivity disorder versus anxiety disorder.

This study examined whether children with attention-deficit/hyperactivity disorder (ADHD) have lower autonomic nervous system (ANS) activity and show less stress reactivity than children with an anxiety disorder. It also explored whether such a difference was accounted for by comorbid oppositional defiant disorder (ODD) or conduct disorder (CD) in some of the ADHD children. Forty-three referred children performed a stress task, during which skin conductance (SCL) and heart rate (HR) levels were measured.