People in areas where the tap water contains lithium are less likely to kill themselves, according to a new Japanese study. The researchers found that the element—used in high doses to treat mood disorders—appeared to "significantly" reduce the suicide rate even when only tiny amounts of it were found in drinking water, the BBC reports.
The scientists believe the cumulative effect of drinking water containing small amounts of lithium over many years may have a protective effect on the brain. They called for more research to be done, but stopped short of suggesting lithium be introduced to water supplies. Mental health experts said the findings definitely merited further investigation, although they warned that large doses of lithium have unpleasant side effects and can be toxic.