A study in Japan has shown a sample population to be less likely to commit suicide after drinking tap water containing lithium. Notably, there is enough lithiu

A study in Japan has shown a sample population to be less likely to commit suicide after drinking tap water containing lithium. Notably, there is enough lithium in the groundwater in certain areas of the US that this "study" has been happening for a long time. El Paso, Texas has high naturally occuring lithium in the groundwater, and is widely reputed to have less violence than comparable cities with less lithium in their water. I haven't read the whole thing, but remarkably, a recent paper seems to have shown this to be true, at least for suicide mortality. Lithium in the public water supply and suicide mortality in Texas (Blüml et al, 2013) There is increasing evidence from ecological studies that lithium levels in drinking water are inversely associated with suicide mortality. Previous studies of this association were criticized for using inadequate statistical methods and neglecting socioeconomic confounders. This study evaluated the association between lithium levels in the public water supply and county-based suicide rates in Texas. A state-wide sample of 3123 lithium measurements in the public water supply was examined relative to suicide rates in 226 Texas counties. Linear and Poisson regression models were adjusted for socioeconomic factors in estimating the association. Lithium levels in the public water supply were negatively associated with suicide rates in most statistical analyses. The findings provide confirmatory evidence that higher lithium levels in the public drinking water are associated with lower suicide rates. https://www.gwern.net/docs/lithium/2013-bluml.pdf https://www.gwern.net/docs/lithium/2013-bluml.pdf Edit: I just realized that the Op Ed linked from the main article mentions the same evidence, although without reference to that particular paper: http://www.nytimes.com/2014/09/14/opinion/sunday/should-we-all-take-a-bit-of-lithium.html http://www.nytimes.com/2014/09/14/opinion/sunday/should-we-a...