Emotion regulation via the autonomic nervous system in children with attention-deficit/hyperactivity disorder (ADHD).

Despite growing interest in conceptualizing ADHD as involving disrupted emotion regulation, few studies have examined the physiological mechanisms related to emotion regulation in children with this disorder. This study examined parasympathetic and sympathetic nervous system reactivity via measures of respiratory sinus arrhythmia (RSA) and cardiac pre-ejection period (PEP) in children with ADHD (n=32) and typically developing controls (n=34), using a novel emotion task with four conditions: negative induction, negative suppression, positive induction, and positive suppression of affect. Both groups showed strong task-response effects in RSA. However, typically developing children showed systematic variation in parasympathetic activity (RSA) depending on both emotion valence (more activation for negative emotion, reduced activation for positive emotion) and task demand (more activation for suppression than induction). In contrast, children with ADHD displayed a stable pattern of elevated parasympathetic activity (RSA) across all task conditions compared to baseline. No group differences in sympathetic activity (PEP) were observed. It is concluded ADHD in childhood is associated with abnormal parasympathetic mechanisms involved in emotion regulation.