The moderating effect of anxiety sensitivity on caffeine-induced hypoalgesia in healthy women

Rationale: Caffeine is an analgesic adjuvant, but also has panicogenic properties. Anxiety sensitivity is a trait vulnerability factor related to negative responses to pain, and is known to moderate negative psychological responses to caffeine. Objectives: The current study sought to investigate whether anxiety sensitivity moderates the effect caffeine has on the pain responses of healthy women. Methods: Caffeine (250 mg) was administered to women pre-selected as high, medium or low in anxiety sensitivity. Measures of arousal and mood were taken before and after drug administration. The cold pressor pain task was used to induce pain. Pain threshold, tolerance, sensory and affective pain responses were also recorded. Results: Caffeine increased systolic blood pressure and mood. Additionally, those low in anxiety sensitivity exhibited caffeine-induced improvement in negative mood (less depressed) and caffeine-related hypoalgesia. Conclusions: These results suggest that the analgesic effects of caffeine may depend on anxiety sensitivity status, and that the fear of bodily sensations should be considered in pain management programmes.