Does an Increase in Depressive Symptoms Lead to an Increase in Functional Impairment or vice versa? Results of the AgeCoDe and AgeQualiDe Study

Abstract

To clarify the link between depressive symptoms and functional impairment among the oldest old longitudinally. Longitudinal data (n = 1,272) were taken from a multicenter prospective cohort study ("Study on Needs, health service use, costs and health-related quality of life in a large sample of oldest-old primary care patients (85+)" [AgeQualiDe]). Functional decline was assessed using the Lawton and Brody Instrumental Activities of Daily Living scale, and the Geriatric Depression Scale was used to measure depressive symptoms. While initial increases in depressive symptoms were associated with subsequent increases in functional impairment, initial increases in functional impairment were not associated with subsequent increases in depressive symptoms. Our results stress the relevance of increases in depressive symptoms for upcoming functional decline among the oldest old. Further longitudinal studies are required to replicate our findings.