Lithium treatment and risk for dementia in adults with bipolar disorder: population-based cohort study

Background Lithium inhibits glycogen synthase kinase-3, an enzyme implicated in the pathogenesis of dementia. Aims To examine the association of lithium and dementia risk in a large claims-based US cohort of publicly insured older adults with bipolar disorder. Method The cohort included individuals >= 50 years diagnosed with bipolar disorder who did not receive dementia-related services during the prior year. Each follow-up day was classified by past-year cumulative duration of lithium use (0, 1-60, 61-300 and 301-365 days). Dementia diagnosis was the study outcome. Anticonvulsants commonly used as mood stabilisers served as a negative control. Results Compared with non-use, 301-365 days of lithium exposure was associated with significantly reduced dementia risk (hazard ratio (HR)=0.77, 95% Cl 0.60-0.99). No corresponding association was observed for shorter lithium exposures (HR= 1.04, 95% Cl 0.83-1.31 for 61-300 days; HR= 1.07, 95% Cl 0.67-1.71 for 1-60 days) or for any exposure to anticonvulsants. Conclusions Continuous lithium treatment may reduce dementia risk in older adults with bipolar disorder. Copyright and usage (C) The Royal College of Psychiatrists 2015.