Relationships between depressive symptoms and descriptions of chronic pain

The present study investigated the relationship between the severity of depressive symptoms and various qualitative and quantitative aspects of pain reported by chronic pain patients. The sample consisted of 73 patients from a heterogeneous pain population admitted to the Victoria General Hospital Pain Management Unit. Patients completed a comprehensive pain evaluation battery that included the Beck Depression Inventory (BDI) and the McGill Pain Questionnaire (MPQ). They rated their loss of desire and ability for various social and recreational activities, and the intensity of their pain for 8 periods of a typical day. Multivariate analyses of variance were used to assess the sensory, affective, and evaluative indices of the MPQ, daily pain intensity ratings, and reported impairment of activities of non-depressed, mildly depressed and moderate/severely depressed patients. The results indicate significant relationships between the degree of depression and (a) the number of sensory descriptors endorsed on the MPQ; (b) pain intensity ratings in the late evening and at bedtime; and (c) reported loss of ability for social and recreational activities. Depression is related to loss of desire for activity in women, but not in men. A discriminant analysis suggests that depressed and non-depressed pain patients can be distinguished with 78% accuracy on the basis of their MPQ Sensory scores, reported loss of ability for activities, and global pain ratings at late evening and bedtime. The findings are discussed in terms of their implications for research as well as for the assessment and treatment of chronic pain patients.