Lithium in drinking water and suicide mortality: The interplay with lithium prescriptions

Background

Little is known about the effects of lithium intake through drinking water on suicide. This intake originates either from natural rock and soil elution and/or accumulation of lithium-based pharmaceuticals in ground water.
Aims
To examine the interplay between natural lithium in drinking water, prescribed lithium-based pharmaceuticals and suicide in Austria.
Method
Spatial Bayesian regressions for males, females and pooled suicide mortality rates were estimated.
Results
Although the expected inverse association between lithium levels in drinking water and suicide mortality was confirmed for males and for total suicide rates, the relationship for females was not significant. The models do not indicate that lithium from prescriptions, assumed to accumulate in drinking water, is related to suicide risk patterns either as an individual effect or as a moderator of lithium levels in drinking water. Gender-specific differences in risk factors and local risk hot spots are confirmed.
Conclusions
The findings do not support the hypotheses that lithium prescriptions have measureable protective effects on suicide or that they interact with lithium in drinking water.