As discussed here in the recent NY Times Magazine, some people are looking at effects of lithium in drinking water:

In The British Journal of Psychiatry earlier this year, the neuropsychiatrist Takeshi Terao and other researchers showed that communities in Japan’s Oita Prefecture with higher levels of naturally occurring lithium in their water supplies had fewer suicides than those with lower levels.

These are low doses compared to those used in pills, and the researchers

contend that the lithium levels in their study are low enough not to cause significant side effects, and that in any case the benefits outweigh the risks.

This is not really new news.  In a 1990 study (abstract here), published in the journal, Biological Trace Elements Research, researchers noted that

Using data for 27 Texas counties from 1978-1987, it is shown that the incidence rates of suicide, homicide, and rape are significantly higher in counties whose drinking water supplies contain little or no lithium than in counties with water lithium levels ranging from 70-170 micrograms/L;

These results suggest that lithium has moderating effects on suicidal and violent criminal behavior at levels that may be encountered in municipal water supplies.

results suggest that lithium at low dosage levels has a generally beneficial effect on human behavior, which may be associated with the functions of lithium as a nutritionally-essential trace element. Subject to confirmation by controlled experiments with high-risk populations, increasing the human lithium intakes by supplementation, or the lithiation of drinking water is suggested as a possible means of crime, suicide, and drug-dependency reduction at the individual and community level.

So, some aberrant behavior might be explained by a deficiency of lithium.  Vitamin L is already taken (it’s anthranilic acid, associated with lactation, as reported here), so we’d have to call it something else…. an Environment Memo T-Shirt to the best suggestion!