Vascular lesions and functional limitations among older adults: does depression make a difference?

BACKGROUND: The association between disability and depression is complex, with disability well established as a correlate and consequence of late life depression. Studies in community samples report that greater volumes of cerebral white matter hyperintensities (WMHs) seen on brain imaging are linked with functional impairment. These vascular changes are also associated with late life depression, but it is not known if depression is a modifier in the relationship between cerebrovascular changes and functional impairment. METHODS: The study sample was 237 older adults diagnosed with major depression and 140 never depressed comparison adults, with both groups assessed at study enrollment. The dependent variable was the number of limitations in basic activities of daily living (ADL), instrumental ADLs, and mobility tasks. The independent variable was the total volume of cerebral white matter lesions or hyperintensities assessed though magnetic resonance imaging. RESULTS: In analyses controlling for age, sex, race, high blood pressure, and cognitive status, a greater volume of WMH was positively associated with the total number of functional limitations as well as the number of mobility limitations among those older adults with late life depression but not among those never depressed, suggesting the association between WMH volume and functional status differs in the presence of late life depression. CONCLUSIONS: These findings suggest older patients with both depression and vascular risk factors may be at an increased risk for functional decline, and may benefit from management of both cerebrovascular risk factors and depression.