History of Bipolar Disorder and the Risk of Dementia: A Systematic Review and Meta-Analysis.

OBJECTIVE: We carried out a systematic review and meta-analysis to evaluate whether history of bipolar disorder (BD) increases the risk of dementia.

METHODS: We searched PubMed and Scopus to identify studies that evaluated the risk of dementia in individuals with a history of BD. A total of 6 studies including 3,026 individuals with history of BD and 191,029 non-BD individuals were included in the meta-analysis.

RESULTS: History of BD significantly increased the risk of diagnosis of dementia (pooled odds ratio: 2.36; 95% confidence interval: 1.36-4.09; z = 3.07, p < 0.001). Evidence of heterogeneity and of publication bias in the analysis was found.

CONCLUSION: History of BD is associated with significantly higher risk of dementia in older adults. Future studies are necessary to evaluate the potential mediators of this association and to evaluate interventions that may reduce the risk of dementia in this population.