Autonomic Readiness for Social Threats in Patients with Social Anxiety Disorder.

Objective: Pathological anxiety is characterized by dysregulated arousal and lower heart rate variability associated with emotional dysregulation. This study explored the connection between peripheral and central autonomic nervous system activity during emotional processing in social anxiety disorder (SAD).

Methods: Thirty-two patients with SAD and 41 healthy controls engaged in a passive viewing task alternating between neutral and angry faces. The root mean square of successive differences (RMSSD) was measured during the resting state (baseline RMSSD) and emotional processing (task RMSSD). We examined the relationships between brain activation during emotional processing and these RMSSD measures.

Results: Unlike the controls, the SAD group exhibited a trend level toward significant correlations of baseline RMSSD with left anterior insula activity during neutral face processing (p = 0.058) and significant correlations with both left anterior insula and right amygdala activities during angry face processing (p = 0.027 and 0.046, respectively). In the controls, task-related RMSSD correlated with neural activities in the right amygdala and right dorsomedial prefrontal cortex during neutral face processing (p = 0.017 and 0.004, respectively), while in the SAD group, a correlation emerged with the right parahippocampal gyrus (p = 0.044). Notably, only in the control group did RMSSD, measured during neutral face processing, significantly correlate with neural activation during the processing of angry faces (p = 0.035).

Conclusion: This study delineates distinct autonomic and neural response patterns to emotional stimuli in SAD patients, highlighting increased autonomic readiness and diminished flexibility in response to social threats.