Late life depression and incident activity limitations: influence of gender and symptom severity.

BACKGROUND Mental disorders, especially depression, are one of the principal causes of disablement. Previous research has been limited partly due to the failure to take into account sub-syndromal states and the very large number of candidate mediating and confounding factors. METHODS Longitudinal associations between baseline depressive symptomatology and activity limitations were examined in a community-dwelling elderly cohort of 3191 participants. Mixed logistic models were used to determine associations between mild or severe depressive symptoms (Center for Epidemiologic Studies-Depression Scale, CES-D), and 7-year incident disability on four limitation scales assessing instrumental and basic activities of daily living, mobility using the Rosow and Breslau scale, and social restriction. RESULTS In men, mild depressive symptomatology was associated with increased incident limitations on instrumental activities of daily living (IADL) (odds ratio (OR) (95% CI)=5.07 (2.25-11.42)). In women, severe depressive symptomatology was related to social restriction (OR (95% CI)=2.36 (1.31-4.25)), IADL (OR (95% CI)=1.89 (1.13-3.15)) and activities of daily living (OR (95% CI)=11.15 (3.43-36.23)). Men and women with a 2-year increase in CES-D score were highly at risk for social restriction and limitations in mobility and IADL. CONCLUSION Depression is an independent predictor of disability in the elderly population; the relation is gender-dependent and varies with symptom load.