Association between late-life depression and vascular risks, executive dysfunction, and adverse outcomes: Secondary analysis of the Canadian Study of Health and Aging

Background: Evidence for the vascular depression hypothesis is inconsistent and the clinical features remain unclear. Studies with longitudinal follow-up are needed to test the validity of clinically defined vascular depression, done here by evaluating vascular risk, neuropsychological and functional differences, and adverse outcomes between depressed and non-depressed subjects. Methods: Secondary analysis, with 964 non-demented subjects, including depressed subjects (n = 140) and non-depressed subjects (n = 824), from the Canadian Study of Health and Aging (CSHA), evaluated for depression, neuropsychological and functional measures, and adverse outcomes in relation to cumulative vascular risk. Results: There were no significant differences between vascular depression and non-vascular depression, but there were significant differences between depressed and non-depressed people. Evaluating a depression/vascular risk profile, depressed people had 2.5 times the odds (95% confidence interval [CI] = 1.61-3.87) of high vascular risk than non-depressed subjects. Depression and vascular risks had cumulative effects on functional impairment, death (hazard ratio [HR] = 1.97,95% CI = 1.35-2.89), and institutionalization (HR = 2.82, 95% CI = 1.43-5.54). Conclusions: Depressed people had significantly increased vascular risk factors, executive dysfunction, and functional impairment and worse 5-year outcomes than did non-depressed people. There were no differences between the vascular depressed and non-vascular depressed groups. The findings provide mixed support for the vascular depression hypothesis.