http://illinois.edu/blog/view/789/95197
There isnt a great deal of data on lithium in groundwater, its not routinely analyzed and concentrations are often below instrument detection limits. The USGS recently published a report of trace elements in groundwater in the U.S. which included a map showing lithium concentrations in about a dozen aquifers. Highest concentrations were found in the Texan Panhandle (part of the High Plains Aquifer) and an unconsolidated sand stream valley aquifer in Wyoming. They stated that concentrations were generally greater in unconsolidated sand and gravel aquifers than in any other aquifer groups.
USGS Li map
So what do you think? A potential widespread benefit for society? Or dangerous government overreach, compulsory mass medication? I have to say, I need to see a lot more data and research before Im convinced that theres a direct causal link between increased lithium and less violent behavior. Seems to me there are a huge number of variables that need to accounted for.