Impaired cardiac profile in adolescents with an increasing trajectory of anxiety when confronting an acute stressor.

Maladaptive patterns of cardiac adjustment to stress in adolescents may reveal their vulnerability to anxiety disorders (ADs). Traditional research in this field has focused on anxiety levels, whereas the time course of anxiety has rarely been considered. Nevertheless, since overall anxiety decreases as adolescence progresses, increasing time courses are clinically relevant and can be associated with maladaptive contextual adjustment. In this study, the cardiac pattern of adjustment to stress in adolescents with increasing anxiety was analysed. A sample of 44 adolescents (M = 14.88 years, SD = 0.53, 45.45% boys) were exposed to a socially relevant stress induction protocol, and their cardiac functioning was recorded. Participants with a trajectory of increasing anxious symptomatology over a 12-month period (n = 24) showed attenuated heart rate levels in the stage of maximum stress in comparison to their non-increasing anxious counterparts (p < 0.05), as well as a heightened pattern of sample entropy throughout the stress induction (p < 0.05). These findings suggest a loss of cardiac flexibility in those adolescents at risk of ADs when confronting an acute stressor.