Depressive symptoms and cognitive decline in elderly people. Longitudinal study.

Abstract

Depressive symptoms are associated with cognitive decline in elderly people, but the nature of their temporal relationship remains equivocal. To test whether depressive symptoms predict cognitive decline in elderly people with normal cognition. The Center for Epidemiologic Study depression scale (CES-D) and the Mini-Mental State Examination (MMSE) were used to evaluate depressive symptomatology and cognitive functioning, respectively. A sample of 1003 persons aged 59-71 years and with a MMSE score of 26 or over was selected. Cognitive decline was defined as a drop of at least 3 points on the MMSE at 4-year follow-up. Baseline high levels of depressive symptoms predicted a higher risk of cognitive decline at 4-year follow-up. The MMSE score of participants with depression was more likely to fall below 26 at 2-year follow-up and to remain below at 4-year follow-up than the MMSE score of those without depressive symptoms. Persistent but not episodic depressive episodes were associated with cognitive decline. High levels of depressive symptoms, when persistent, are associated with cognitive decline in a sample of elderly people.