Parasympathetic withdrawal indexes risk for emotion dysregulation in children with autism spectrum disorder.

Children with autism spectrum disorder (ASD) experience significant difficulties with emotion regulation. Theory and empirical evidence suggest substantial biological contributions to regulatory challenges, which may be related to core ASD symptoms. Respiratory sinus arrythmia (RSA) is a measure of parasympathetic nervous system activity that serves as a putative biomarker for emotion regulation. Higher baseline RSA and more RSA reactivity (parasympathetic withdrawal; RSA-R) in response to challenge appear adaptive in non-clinical populations, but existing evidence for children with ASD remains inconclusive. The current study examined correlates of observed emotion dysregulation in 61 children with ASD between the ages of 6 and 10 years, including ASD symptom levels as well as both baseline RSA and concurrent RSA reactivity. Consistent with previous research, ASD symptom level was significantly correlated with observed dysregulation whereas additional factors such as child IQ were not. Baseline RSA was unrelated to observed dysregulation, but higher RSA reactivity predicted concurrent dysregulation above and beyond the contribution of child ASD symptoms. Findings contribute to an emerging understanding of dysregulation in these children, raise questions about the utility of traditional baseline RSA measures for this population, and clarify the functional significance of RSA reactivity as a risk factor for emotion dysregulation in children with ASD.