Depression and the chronic pain experience.

The present study examined the relationship between depression and a constellation of pain-related variables that describe the experience of chronic pain patients. Thirty-seven depressed and 32 non-depressed heterogeneous chronic pain patients were identified through structured interviews, use of standardized criteria and scores on the Beck Depression Inventory (BDI). The 2 groups were compared on demographic variables and scores on the Marlowe-Crowne Social Desirability scale (MC), as well as measures of disability and medication use, pain severity, interference due to pain and reported pain behaviors. The depressed group was found to be younger and to score lower on the MC than the non-depressed group. Multivariate analyses of covariance (MANCOVA), using age and MC as covariates, revealed that depressed chronic pain patients, relative to their non-depressed counterparts, reported greater pain intensity, greater interference due to pain and more pain behaviors. There were no group differences on the measures of disability and use of medications. The results provide further support for the importance of incorporating depression into clinical and theoretical formulations of chronic pain. Future use of structured interviews and standardized criteria for diagnosing depression may clarify some of the inconsistencies found in the literature.