[ng12]

We don't even know that lithium deficiency is definitively a thing, it's not like there's an established RDA. There could be any number of reasons why it's correlated with lower violent crime.

[vanderZwan]

Lithium is prescribed in bipolar disorder, wouldn't that imply it is reasonably understood?

[magic_beans]

"Reasonably understood" is not the same as "Oh, hey, this seems to work."