Autonomic Nervous System Functioning and Internalizing Disorders in Adolescents

Abstract

The autonomic nervous system (ANS) is used to describe the sympathetic (activation) and parasympathetic (inhibition) nervous system. Imbalance of the ANS is associated with negative cardiac health events and death. Coincidentally, those with internalizing or depressive symptoms and disorders have a higher occurrence rate of similar cardiac-related problems. Important to consider is the developing nervous system in adolescents with internalizing problems since changes taking place now could predispose them to future health risks. Some of the ways in which ANS dysregulation is evidenced are higher or lower heart rate (HR) or blood pressure (BP) level at rest, and exaggerated or blunted heart rate reactivity (HRR) or blood pressure reactivity (BPR) to stress. ANS differences could be a link between psychological and cardiac health in youth with internalizing problems. This study aimed to address some of the gaps in previous studies on ANS differences that have found inconsistent results by considering a larger sample of male and female adolescents with well-defined problem profiles. Participants were 215 adolescents who were identified as having elevated behavioral or emotional problems and healthy controls. ANS was measured using HR and BP as well as HRR and BPR within the context of two social stressors. Results revealed significant gender differences, with males having higher systolic blood pressure (SBP) resting level and reactivity while females showed higher HRR. When controlling for externalizing problems, males evidenced a positive correlation between internalizing problems and resting DBP, as well as with resting MAP. Internalizing problems in males were negatively correlated with DBP reactivity and MAP reactivity when controlling for externalizing symptoms. Emerging differences in ANS functioning in adolescents could have important health implications for future health and may explain current trends. The results of this study may suggest important ways in which regulating ANS functioning in adolescents may prevent emotional problems, as well as more long-term negative health consequences.