The Effect of Controlling for Anxiety and Depression upon the Threshold for Pressure Pain in Three Comparison Groups

Objectives: A number of investigations have suggested that thresholds for pressure pain may be lowered in myofascial dysfunction syndromes, infibromyalgia, and in certain gastrointestinal disorders. We investigated the relationships between anxiety, depression and pressure pain thresholds in normal controls compared with two groups of patients with abdominal complaints, namely Crohn's disease and the syndrome of abdominal bloathing. Methods: Subjects meeting clinical criteria for one of the entry conditions completed the Hospital Anxiety and Depression Scale and were examined at 3 musculoskeletal sites with a pressure algometer to determine pain thresholds. Results: Crohn's disease patients exhibited a significantly lower-than-normal threshold not seen with the bloating subjects. That remained true even after controlling for sex, weight, intensity of pain, anxiety, and depression, variables which showed little impact on thresholds. Females exhibited lower thresholds than males while body weight was directly related to threshold. Conclusions: These findings failed to support the hypothesis that patients with the seemingly more functional bloating syndrome would exhibit a lower threshold for pressure pain than Crohn's disease.