Sympathetic arousal moderates self-reported physiological arousal symptoms at baseline and physiological flexibility in response to a stressor in generalized anxiety disorder.

Compared to controls, individuals with generalized anxiety disorder (GAD) often fail to exhibit expected changes in physiological arousal in response to laboratory stressors. Nevertheless, individuals with GAD often report significant subjective arousal. We sought to assess the degree of sympathetic arousal in individuals with GAD and controls and the impact such arousal had on self-reported physiological arousal and response to an emotional challenge. Degree of baseline sympathetic arousal moderated the self-report of physiological arousal in non-comorbid GAD at baseline such that within this group, higher levels of sympathetic arousal predicted reports of heightened physiological arousal compared to controls. Overall, individuals with GAD exhibited no significant changes in arousal in response to the emotional challenge. However, basal sympathetic arousal moderated degree of change such that non-comorbid GAD participants low in baseline sympathetic arousal exhibited changes in arousal similar to controls in response to the stressor. That basal sympathetic arousal moderated both self-reported arousal at baseline and sympathetic response to a stressor suggests important physiological heterogeneity in GAD, wherein only those individuals with heightened tonic sympathetic arousal report accompanying symptoms and display diminished sympathetic reactivity.