Effects of Autonomic Nervous System Functioning and Tornado Exposure on Long-Term Outcomes of Aggressive Children.

This study examined whether pre-disaster indicators of sympathetic and parasympathetic activity moderated the relation between degree of disaster exposure from an EF-4 tornado and changes in the externalizing and internalizing behavior problems of children at-risk for aggression. Participants included 188 children in 4th-6th grades (65% male; 78% African American; ages 9-13) and their parents from predominantly low-income households who were participating in a prevention study when the tornado occurred in 2011. Fourth-grade children who exhibited elevated levels of aggressive behavior were recruited in three annual cohorts. Parent-rated externalizing and internalizing problems were assessed prior to the tornado (Wave 1; W1), and at 4-12 months (W2), 16-24 months (W3), 42-28 months (W4) and 56-60 months (W5) post-tornado. Children's pre-tornado Skin Conductance Level (SCL) reactivity and Respiratory Sinus Arrhythmia (RSA) withdrawal were assessed at W1 using SCL and RSA measured during resting baseline and during the first 5 min of the Iowa Gambling Task (IGT). Children and parents reported their exposure to tornado-related trauma and disruptions at Wave 3. Children displayed less reduction in externalizing problems if there had been higher child- or parent-reported tornado exposure and less RSA withdrawal, or if they had lower parent-reported TORTE and less SCL reactivity or lower SCL baseline. Highlighting the importance of children's pre-disaster arousal, higher levels of disaster exposure negatively affected children's level of improvement in externalizing problems when children had less vagal withdrawal, and when tornado exposure disrupted the protective effects of higher SCL reactivity and higher SCL baseline.