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

Abstract

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.

Conflict of interest statement

Declaration of interest

In the past 3 years B.S.D. has received payment for lectures from Novartis and had travel/meeting expenses covered by Pfizer. M.A.B. received remuneration for neuropsychological assessment services on a fee-for-service basis, for clinical trials conducted by Northstar Neuroscience and Medtronic and from Fox Learning Systems for developing computerised neuropsychological tasks for an NIH-funded study. The following pharmaceutical companies provide pharmaceutical supplies for C.F.R.’s NIH-sponsored work: Bristol-Myers Squibb, Forrest Laboratories, Lilly and Pfizer.

Figures

Fig. 1

Flow chart of the study search and selection for inclusion in the meta-analysis. a. No description of sample setting, of baseline diagnosis of depression or the outcome diagnosis of dementia/Alzheimer’s disease, risk measure not calculated or not reported.

Fig. 2

Forest plot for the risk of all-cause dementia in participants with late-life depression.

Fig. 3

Forest plot for the risk of incident Alzheimer’s disease in participants with late-life depression.

Fig. 4

Forest plot for the risk of incident vascular dementia in participants with late-life depression.