Relationship between Lithium Levels in Drinking Water and Suicide Rates: A Nationwide Study in Lithuania

Objective: To investigate an association of lithium levels in the drinking water with suicide mortality rates in Lithuania. Methods: Samples from public drinking water systems were taken in all districts of Lithuania. Lithium levels were determined using the ion chromatography method. For the statistical calculations, lithium levels were averaged per district municipality and plotted against suicide standardized mortality rates (SMR) per 100,000 populations, within the 5-year period from 2012 to 2016. Results: We found that lithium concentrations in drinking water were significantly negatively associated with total suicide rates in a nonlinear way. Conclusion: Lithium intake with drinking water may affect suicide rates in some geographical areas.