Prospective study on the relationship between depressive symptoms and chronic musculoskeletal pain.

Chronic pain and depression often coexist, but there is still uncertainty about the nature of this relationship. Virtually all the available data are cross-sectional and therefore do not clarify the causal relationship between the two variables. In epidemiological studies, chronic pain has often been defined fairly liberally in terms of the actual duration. In this study, the definition of chronic pain was based upon self-reports of pain present for most of the days in at least 1 month of the 12 months preceding the interview. We tested the hypotheses that depression causes pain and that pain causes depression in a sample of 2324 subjects who were assessed for the presence of musculo-skeletal pain and the presence of depression, using for the latter a standardized published instrument called the Center for Epidemiologic Studies Depression scale (CES-D). The subjects were first examined using the National Health and Nutrition Survey (NHANES 1) of the United States National Center for Health Statistics from 1974 to 1975, and were followed-up from 1981 to 1984. Those with data on both occasions represent 76% of an initial population of 3059 persons. On logistic regression analysis depressive symptoms at year 1 significantly predicted the development of chronic musculo-skeletal pain at year 8 with an odds ratio of 2.14 for the depressed subjects compared with the non-depressed subjects. In patients in whom pain was present at baseline no socio-demographic variable alone predicted its persistence; however, male sex and white race together with 2 items of the CES-D did predict the persistence of existing pain.(ABSTRACT TRUNCATED AT 250 WORDS)