Heart rate and autonomic response to stress after experimental induction of worry versus relaxation in healthy, high-worry, and generalized anxiety disorder individuals

Generalized anxiety disorder (GAD) is the most commonly occurring anxiety disorder and has been related to cardiovascular morbidity such as cardiac ischemia, sudden cardiac death, and myocardial infarction. Both GAD and its cardinal symptom – worry – have been shown to promote muted physiological reactivity in response to laboratory and ecological stressors. Importantly, no study to date has examined the concurrent and relative contributions of trait and state worry within healthy controls, (non-clinical) high trait-worry controls, and GAD participants. The present study examined heart rate (HR), respiratory sinus arrhythmia (RSA), and salivary alpha-amylase (sAA) responses to laboratory stress during and following the experimental induction of worry versus relaxation in healthy controls (n = 42), high trait worriers (n = 33) and participants with GAD (n = 76). All groups exhibited increased HR and decreased RSA in response to the stressor, with no differences by condition. Baseline sAA significantly moderated HR and RSA reactivity, such that higher sAA predicted greater increases in HR and decreases in RSA. There was a significant group by baseline sAA interaction such that in GAD, higher baseline sAA predicted decreased change in sAA during stress, whereas higher baseline sAA predicted greater sAA change in healthy controls. High-worry controls fell non-significantly between these groups. The present study provides additional evidence for the effect of worry on diminished HR stress response and points to possible suppression of adrenergic sympathetic stress responses in GAD.

► Baseline salivary alpha-amylase (sAA) moderated response of heart rate (HR) and respiratory sinus arrhythmia (RSA) across all groups such that higher baseline sAA promoted greater increase in HR and decrease in RSA in response to stress.
► Baseline sAA promoted increased sAA response to stress in healthy controls.
► In individuals with GAD, higher baseline sAA created a suppressed sAA response to stress.
► State worry predicted lesser HR response to stress across all groups and conditions.
► Higher RSA predicted lower HR across all groups and conditions.