Assessing Autonomic Regulation Under Stress with the Yale Pain Stress Test in Social Drinking and Alcohol Use Disorder.

High levels of stress and individual differences in acute stress responses are important predictors of chronic illness. This study examined the effects of stress and Alcohol Use Disorder (AUD) on heart rate variability (HRV) using the Yale Pain Stress Test (YPST), adapted from the well-established Cold Pressor Test (CPT). The YPST characterized three key (time periods) phases of the cardiovascular stress response to repeated trials of a pain-stress versus no pain-stress control condition: pre-stress baseline, acute reactivity, and recovery, using HRV as a physiological marker. Participants included 24 individuals who engaged in social drinking and 21 participants with AUD, all recruited from the Greater New Haven area. They were screened for psychiatric or medical conditions and other substance use disorders using DSM-5 criteria. Results showed significant main effects of stress condition and time across HRV metrics. While no significant three-way interaction among time period, condition, and drinking group was observed, there were significant condition × time period effects and group × condition effects. Participants with AUD exhibited lower high-frequency (HF) and low-frequency (LF) HRV during stress exposure compared to the recovery phase. They also showed a less dynamic LF/HF ratio during stress relative to social drinking controls, suggesting greater sympathetic dominance. In contrast, participants who engaged in social drinking displayed autonomic flexibility across time periods. Findings suggest that individuals with AUD experience blunted autonomic reactivity and reduced HRV recovery following stress, highlighting diminished physiological flexibility potentially indicating risk for long-term stress-related chronic diseases. The results underscore the importance of evaluating autonomic function in clinical care and recovery planning for individuals with AUD.