Friday, February 1, 2008

Autonomic Correlates of ADHD and ODD in Preschool Children

Cromwell, S.E., Beauchaine, T.P., Gatzke-Kopp, L., Sylvers, P., Mead, H., & Chipman-Chacon, J. (2006). Autonomic Correlates of Attention-Defecit/Hyperactivity Disorder and Oppositional Defiant Disorder in Preschool Children. Journal of Abnormal Psychology, Volume 115, Number 1, 174-178.

Conduct disorder in adolescence and antisocial behavior in adults has been shown to be marked by autonomic underarousal. This study attempted to see if much younger, at-risk pre-schoolers are autonomically similar to older externalizing children and adults. Firstly, the study found that pre-school children with ADHD and ODD showed attenuated EDR, a measure of sympathetic nervous system (SNS). Decreased SNS activity is thought to be a marker of disinhibition. Secondly, the study found ADHD and ODD pre-schoolers have attenuated SNS-linked cardiac activity, which serves as a marker of reward sensitivity. Children with underactive reward systems may engage in reward-seeking behavior to compensate for a chronically suppressed dopaminergic subsystem. Finally, as compared with controls, the paper showed no substantial differences in these ADHD/ODD groups in RSA, a marker of parasympathetic nervous system (PNS) activity, and more generally, emotional regulation. The results support the hypothesis that even very young ADHD and ODD children are similar in autonomic biology to older antisocial groups. However, these preschool years may represent a critical period during which noradrenergic, serotonergic, and dopaminergic systems that govern behavioral control are most vulnerable to long-term changes, and importantly, emotional dysregulation, a hallmark of most psychological disorders, may be positively affected through early detection and intervention during this timeframe.

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