Effect of perceived pain in the relationship between depressive symptoms and functional status in older adults

The cross-sectional relationship between depression and various dimensions of functional impairment in older adults is well documented, but the role of perceived pain in this relationship is not. We explored the association between perceived pain, depressive symptoms, and three dimensions of physical functioning in the 1993 AHEAD, a nationally representative sample of community-dwelling older adults. For these analyses, all non-proxy participants age 60+ were included (n=7318). Depressive symptoms were measured using an eight-item CES-D, and participants reported whether they were often bothered by pain. Difficulties within three dimensions of function were assessed: 1) six ADL items, 2) five IADL tasks, and 3) four items concerning strength/mobility. In multivariate analyses of variance (MANOVA) controlling for age, sex, race, marital status, education, self-perceived health, and cognitive functioning, the interaction between depressive symptoms and perceived pain predicting function was significant (Wilks' Lambda p<.0001), suggesting the impact of depressive symptoms on functional status was moderated by pain. In follow-up ‘univariate' tests, both depressive symptoms and pain were associated with more ADL limitations, with a significant interactive effect. Pain was not significantly associated with number of IADL limitations in persons without depressive symptoms, but individuals with both depression and pain had significantly more limitations than those with depressive symptoms alone. Both pain and depression were associated with limitations in strength/mobility, but the interaction was not significant. These findings support the concept of perceived pain as an important component of the relationship between depression and functional status in older adults.