Bipolar disorder and the risk of developing dementia – a systematic review and meta-analysis

PURPOSE OF REVIEW: To present an up-to-date systematic review and meta-analysis on the risk of dementia in patients with bipolar disorder. RECENT FINDINGS: We included 22 studies investigating the risk of developing dementia among patients with bipolar disorder of which 21 studies provided data for the meta-analysis, comprising a total of 185 306 patients with bipolar disorder and 10 702 744 participants without bipolar disorder. Random effects meta-analysis showed an increased risk of being diagnosed with dementia in patients diagnosed with bipolar disorder [odds ratio (OR): 3.13 (95% CI: 2.40-4.09), I2 = 99.8%, 21 studies]. In a secondary analysis excluding studies with overlapping populations, the pooled effect estimate was OR = 2.60 (95% CI 1.76-3.85, I2 = 99.9%, 11 studies). The evidence was uncertain due to substantial and unexplained between-study heterogeneity, methodological limitations, and risk of bias in the included studies. SUMMARY: Patients with bipolar disorder have an increased risk of developing dementia, but the evidence is uncertain.