Examining the moderating role of intolerance of uncertainty on pain tolerance and craving in patients with chronic pain and alcohol use disorder.

Chronic pain (CP) and alcohol use disorder (AUD) frequently co-occur, yet the psychological factors underlying their interaction remain unclear. Intolerance of uncertainty (IU) - a cognitive trait linked to distress in unpredictable situations - may influence pain management and coping behaviors in these populations. This study examined whether IU moderates pain and alcohol craving responses to a pain-related stressor in individuals with CP and AUD. Fifty-five adults aged 18-65 years were enrolled, including individuals with CP only (n = 20), AUD only (n = 14), CP + AUD (n = 8), and healthy controls (n = 13). Participants completed a self-report measure of IU and the Yale Pain Stress Test (YPST), an adaptation of the Cold Pressor Test, designed to elicit pain-related stress. Behavioral pain tolerance, subjective pain and alcohol craving were assessed across two experimental sessions, one with exposure to an ice-cold water stressor and the second with a warm-water control condition. Exposure to the pain-related stressor significantly reduced behavioral pain tolerance and increased subjective pain across all groups, and also heightened alcohol craving, particularly in individuals with AUD. IU moderated the pain experience during pain-related stress: in the CP + AUD group, higher IU was associated with lower pain tolerance, whereas in the AUD group, higher IU was correlated with greater pain tolerance. IU also moderated craving responses, with higher IU predicting increased craving in individuals with both CP and AUD. These preliminary findings highlight IU as a potential treatment target, suggesting that interventions aimed at improving uncertainty tolerance may enhance pain coping and reduce stress-driven alcohol-seeking behaviors in vulnerable populations.