Interactive effects of childhood maltreatment and tonic respiratory sinus arrhythmia on young adults' depressive symptoms.

The goal of the current study was to investigate the moderating effect of tonic respiratory sinus arrhythmia (RSA) in the relation between childhood maltreatment and depression symptoms among young adults. A total of 98 participants (70 women) aged 17-22 years completed questionnaires on childhood maltreatment and depressive symptoms. RSA data were obtained during a resting condition in the laboratory. Results indicated that childhood maltreatment interacted with tonic RSA to predict depressive symptoms, even after controlling for age and body mass index (BMI) of each participant. Specifically, higher levels of childhood maltreatment were associated with higher levels of depressive symptoms, but only among young adults who exhibited lower tonic RSA. The results indicated that the association between childhood maltreatment and depressive symptoms depends on young adults' physiological functioning/flexibility. Findings suggest that consideration of external environmental factors in combination with internal physiological factors is critical to understand young adults' mental health.