Heart Rate Variability in Children and Adolescents with Autism, ADHD and Co-occurring Autism and ADHD, During Passive and Active Experimental Conditions - Journal of Autism and Developmental Disorders
Source : https://link.springer.com/article/10.1007/s10803-021-05244-w
Despite overlaps in clinical symptomatology, autism and ADHD may be associated with opposite autonomic arousal profiles which might partly explain altered cognitive and global functioning. We investigated autonomic arousal in 106 children/adolescents with autism, ADHD, co-occurring autism/ADHD, and neurotypical controls. Heart rate variability was recorded during resting-state, a 'passive' auditory oddball task and an 'active' response conflict task.
Heart rate variability was recorded during resting-state, a ‘passive’ auditory oddball task and an ‘active’ response conflict task. Autistic children showed hyper-arousal during the active task, while those with ADHD showed hypo-arousal during resting-state and the passive task. Irrespective of diagnosis, children characterised by hyper-arousal showed more severe autistic symptomatology, increased anxiety and reduced global functioning than those displaying hypo-arousal, suggesting the importance of considering individual autonomic arousal profiles for differential diagnosis of autism/ADHD and when developing personalised interventions.
• Source: Scientific Reports
• Conclusion/Relevance: “In the present study, we found evidence of hyper-arousal in autism, reflecting reduced activity of the parasympathetic nervous system especially during more demanding tasks and activities, and hypo-arousal in ADHD, associated with reduced functioning of the sympathetic nervous system especially during resting-state and less engaging tasks. We also found that children with a diagnosis of autism or ADHD could be sub-grouped based on their autonomic arousal profile; and that those with a profile of hyper-arousal displayed more severe social and communication difficulties, increased anxiety, and reduced global functioning.”
• The authors suggested that future researchers investigate the links between dysregulated autonomic arousal and transdiagnostic symptomatologic domains, such as anxiety, behavioral difficulties, mood, and emotional dysregulation. These factors could impact adaptive, global/cognitive functioning, and treatment response in autism and ADHD.
• Measurements taken included heart rate variability (HRV), the Cardiac Sympathetic Index (CSI) and the Cardiac Vagal Index (CVI) in cohorts of children with autism, ADHD, co-occurring autism and ADHD, and neurotypical children. The investigators included three experimental tasks: a resting-state period, a passive attention task, and an active response conflict task.
• This study had certain limitations. First, findings based on the experimental design may not translate to real-world settings. Second, not all child participants completed all tasks. Third, the researchers could not include children with ADHD on non-stimulant medications due to longer washout periods needed.