A study carried out in June of 2011 demonstrated that drinking water contaminated with lithium could actually lower suicide rates. So should lithium be added as a supplement to the water supply, as is done with fluoride?
In the study, 6,460 samples of drinking water were tested across 99 districts in Austria. Districts with higher levels of lithium tended to report lower suicide rates. In some areas lithium occurs naturally in the water supply, likely leached out of rocks and stones.
The results weren’t terribly shocking, as lithium has been used for decades to treat depression. This was the first time its effect was measured based on trace amounts within drinking water, however.