Bipolar disorder and risk of all-cause and specific dementia: a systematic review and meta-analysis
Year: 2026
Type: review
Study designs: Systematic Review, Meta-Analysis
Abstract: Background: Bipolar disorder (BD) is associated with cognitive impairment and an increased risk of dementia; however, the magnitude of this association and subtype-specific risk patterns remain unclear. This systematic review and meta-analysis quantified the associations between BD and the risks of all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD), and explored potential sources of between-study heterogeneity. Methods: PubMed, Embase, the Cochrane Library, and Web of Science were searched from inception to September 15, 2026. Eligible cohort and case-control studies reported adjusted effect estimates for the association between BD and dementia. Hazard ratios and odds ratios were converted to risk ratios (RRs) prior to quantitative synthesis. Random- or fixed-effects models were applied according to heterogeneity. Leave-one-out sensitivity analyses, Egger's test for publication bias, and subgroup analyses stratified by follow-up duration, sex, age at BD onset, and study design were conducted. Results: = 71.7%). Estimates for all-cause dementia and VaD were robust in sensitivity analyses, whereas the AD estimate was sensitive to the exclusion of individual studies and should therefore be interpreted cautiously. The association between BD and increased dementia risk was observed across the examined subgroups. Formal tests for subgroup differences showed no statistically significant differences according to sex or age at BD onset. Conclusion: BD is associated with an increased risk of all-cause dementia, AD, and VaD. However, substantial between-study heterogeneity and the limited evidence available for specific dementia subtypes warrant cautious interpretation of the pooled estimates. Further high-quality longitudinal studies are needed to clarify the factors underlying heterogeneity and subtype-specific associations. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier [CRD420261395626].
Source: Frontiers in Aging Neuroscience
Authors: Zihan Gao, Meiling Ren, Ruiji Yang, Jiahui Yu
Institution: Shanxi Medical University
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7221701802