Late-life depression and risk of vascular dementia and Alzheimer's disease: systematic review and meta-analysis of community-based cohort studies

Background Late-life depression may increase the risk of incident dementia, in particular of Alzheimer's disease and vascular dementia. Aims To conduct a systematic review and meta-analysis to evaluate the risk of incident all-cause dementia, Alzheimer's disease and vascular dementia in individuals with late-life depression in population-based prospective studies. Method A total of 23 studies were included in the meta-analysis. We used the generic inverse variance method with a random-effects model to calculate the pooled risk of dementia, Alzheimer's disease and vascular dementia in older adults with late-life depression. Results Late-life depression was associated with a significant risk of all-cause dementia (1.85, 95% CI 1.67-2.04, P<0.001), Alzheimer's disease (1.65, 95% CI 1.42-1.92, P<0.001) and vascular dementia (2.52, 95% CI 1.77-3.59, P<0.001). Subgroup analysis, based on five studies, showed that the risk of vascular dementia was significantly higher than for Alzheimer's disease (P = 0.03). Conclusions Late-life depression is associated with an increased risk for all-cause dementia, vascular dementia and Alzheimer's disease. The present results suggest that it will be valuable to design clinical trials to investigate the effect of late-life depression prevention on risk of dementia, in particular vascular dementia and Alzheimer's disease.