Early deprivation and autonomic nervous system functioning in post-institutionalized children.

The relations between early deprivation and the development of the neuroendocrine and central components of the mammalian stress response have been examined frequently. However, little is known about the impact of early deprivation on the developmental trajectories of autonomic function. Children adopted between 15-36 months from institutional care were examined during their first 16 months post-adoption (N = 60). Comparison groups included same-aged peers reared in their birth families (N = 50) and children adopted internationally from overseas foster care (N = 46). The present study examined trajectories of baseline autonomic nervous system function longitudinally following entry into adopted families. Post-institutionalized children had higher sympathetic tone, measured by pre-ejection period (PEP). Individual differences in PEP soon after adoption served as a mediator between early deprivation and parent-reported behavioral problems 2 years post-adoption. There were no group differences in parasympathetic function, indexed by respiratory sinus arrhythmia. All three groups showed similar trajectories of ANS function across the 16 month period.