Individuals with anxiety disorders show both excessive and blunted vagally mediated heart rate variability (vmHRV) reactivity to stress. Scholars have suggested that differences in cognitive control could explain such heterogeneity, but this proposition has not been tested. The present study hence investigated the moderating effect of executive functions, particularly inhibitory control, on the relationship between anxiety symptoms and vmHRV reactivity.
We evaluated anxiety symptoms (a diagnostic interview with parents) and executive functions (parent-reported questionnaire) in 262 six-year-olds from a community sample. vmHRV responses to neutral tasks and stressors were analyzed using latent growth curve modeling.
Results supported a moderating effect of inhibitory control; children with more anxiety symptoms and enhanced inhibitory control showed a blunted decrease in vmHRV in response to stressors. In contrast, counterparts with impaired inhibitory control evinced an excessive decrease in vmHRV. Children with no anxiety symptoms did not differ in vmHRV reactivity, independent of the level of inhibitory control.
The results could indicate that anxious children with enhanced inhibitory control successfully utilized a cognitive avoidance strategy (i.e. verbal worry) to inhibit expected autonomic arousal in response to threat. Clinical implications are discussed.