Lithium and risk of cardiovascular disease, dementia and venous thromboembolism.

Objective: To determine if long-term lithium treatment is associated with protective effects or increased risk of vascular, neurological, and renal disorders.

Methods: Using nationwide registers, we included all citizens of Finland with dispensations of lithium for three or more consecutive years between 1995 and 2016. We identified 9698 cases and matched 96,507 controls without lithium treatment. Studied outcomes were vascular, neurological, renal disorders, and suicide. Analyses were performed applying Cox proportional hazards modeling in full cohort and in further subcohort analysis of individuals with a comparable diagnosis of mood or psychotic disorder.

Results: Lithium users had a significantly higher overall disease burden compared to matched population controls, including a higher risk of cardiovascular and cerebrovascular disorders and dementia. However, compared to individuals with a diagnosis of mood or psychotic disorders without lithium treatment, we observed a lower risk of cardiovascular and cerebrovascular disorders (HR = 0.80, 99% CI = 0.73-0.89), and no significant difference for dementia (HR = 1.15, 99% CI = 0.99-1.33), in lithium users. Pulmonary embolism was more common in the lithium-treated cases both in comparison to the general population (HR = 2.86, 99% CI = 2.42-3.37) and in comparison to the psychiatric subcohort (HR = 1.68, 99% CI = 1.31-2.17). Similarly, the risks of Parkinson's disease and kidney disease were higher in both comparisons.

Conclusions: We conclude that individuals prescribed lithium have a lower risk of cardiovascular and cerebrovascular disease, but no marked effect on dementia, compared to individuals with a mood or psychotic disorder not prescribed lithium. Venous thromboembolism, Parkinson's disease, and kidney disease were significantly more prevalent in individuals prescribed lithium.