Costly pain avoidance and its impact on the modulation and extinction of visceral pain-related fear.

Along the gut-brain axis, visceral pain demonstrably evokes emotional learning and memory processes shaping behavior in clinically relevant ways. Avoidance motivated by learned fear may constitute a major obstacle to treatment success in extinction-based interventions. However, the effects of avoidance on visceral pain-related fear extinction remain poorly understood. By implementing an ecologically valid experimental protocol, we investigated how costly avoidance affects the modulation and extinction of visceral pain-related fear. Thirty-three healthy volunteers underwent conditioning with visual cues (conditioned stimuli; CS,CS) consistently followed by visceral pain or remaining unpaired. During avoidance, participants decided to avoid or receive pain upon confronting CS. Avoidance decisions resulted in pain omission in some trials, while in others, participants experienced unpredictable pain. During extinction, CS were presented unpaired. CS valence, fear, and trial-by-trial decisions were analyzed. Avoidance decisions depended on prior experiences, with the highest probability of avoidance following successful pain omission. Negative CS valence and fear remained elevated across avoidance and extinction. Learned fear and more avoidance decisions explained 57% variance in sustained CS fear. Our findings indicate that avoidance, which provides short-term absence of pain even when followed by unpredictable pain, motivates its maintenance. However, it perpetuates pain-related fear and may impede extinction, with implications for persisting symptoms and therapeutic outcomes in chronic visceral pain.