The relationship between depression and pain language in cancer and chronic non-cancer pain patients.

The present study investigated the relationship between depression and pain description among cancer and chronic non-cancer pain patients in a large outpatient sample. Participants consisted of 312 patients (158 men and 154 women) attending a pain management clinic at a comprehensive cancer institute. Sixty-one percent of the patients (190/312) were experiencing pain related to cancer and 39% (122/312) were experiencing chronic nonmalignant pain. Multivariate analyses of covariance were used to assess differences in the sensory and affective indices of the McGill Pain Questionnaire (MPQ) associated with depression and type of pain. Current pain intensity was the covariate. The results indicated that the MPQ affective and sensory intensity scales did not significantly differ among patients with cancer and chronic non-cancer pain. There were also no significant differences in the percentage of affective and sensory pain descriptors chosen by these patients. However, depression significantly influenced MPQ pain description. Depressed patients with pain scored higher on the affective pain intensity dimension of the MPQ than non-depressed patients with pain (P < 0.001). Depressed patients also chose more affective pain descriptors than non-depressed patients (P < 0.001). Chi-square analyses revealed that depressed and non-depressed pain patients made significantly different choices on four of the five MPQ affective adjective lists. There were no differences in the sensory pain index or the percentage of sensory pain descriptors based on depression. These findings are discussed in terms of their clinical implications and their relationship to the existing literature.