Psychosocial factors associated with pain intensity, pain-related interference, and psychological functioning in persons with multiple sclerosis and pain.

Biopsychosocial models of chronic pain that recognize psychological and environmental factors as important aspects of adjustment to pain have been proposed for understanding chronic pain and related suffering in persons with multiple sclerosis (MS), but such models have not been empirically tested. The objective of this study was to test such a model by evaluating the associations of several psychosocial variables (i.e., pain-related catastrophizing, perceived social support, pain beliefs, and pain coping) with pain intensity, pain interference with functioning, and psychological functioning in persons with chronic pain and MS, after controlling for demographic and disease-related factors. Participants were 125 community-dwelling persons with MS and pain who completed a mailed questionnaire that included measures of pain intensity and interference, psychological functioning, catastrophizing, social support, and pain beliefs and coping. The psychosocial variables accounted for an additional 25% of the variance in average pain intensity after controlling for demographic and disease-related variables (p<.001). These variables explained an additional 22% of the variance in pain-related interference (p<.001) and 43% of the variance in psychological functioning (p<.001), after adjusting for demographic and MS-related variables and average pain intensity. Catastrophizing was consistently and independently associated with all criterion measures, whereas social support, pain beliefs, and pain coping were associated with some criterion measures but not others. The results provide empirical support for a biopsychosocial understanding of chronic pain in MS and suggest that specific psychosocial factors (e.g., catastrophizing) may be important regarding adjustment to pain in persons with MS.