Abstract
Recent studies have revealed evidence for interactions between autonomic nervous system (ANS) activity, indexed by saliva alpha amylase (sAA), and hypothalamic-pituitary-adrenocortical activity, in predicting psychological functioning. The present study extends this work by examining individual differences in sAA and cortisol stress reactivity in relation to behavioral and emotional adjustment in youth. Participants were 56 healthy children (age 7-16). sAA, cortisol, and other physiological and affective responses were measured before, during, and after stressor tasks (either performance or peer rejection). Basal and stress responsive sAA and cortisol as well as their interactions were assessed in relation to externalizing and internalizing behaviors and trait anxiety. sAA was positively related to anxiety, while sAA reactivity moderated associations between cortisol reactivity and problem behavior. Results highlight the importance of measuring multiple physiological systems to elucidate mechanisms underlying behavioral and emotional dysregulation.