> I can't but help wonder whether higher levels of lithium also correlate with a clean water supply, which would indicate a more affluent community. It may simply be the case that those areas with cleaner water have a better economy, and thus less crime, etc.
I don't think it would. Typically both rich and poor communities would only be enforcing the FDA ceiling on lithium levels, which seems to be high enough that remediation is rarely (ever?) necessary, so rich/poor wouldn't correlate with levels much if all. The confounds which have come up as particularly plausible tend to deal with locations of mental hospitals, urban vs rural, and local food consumption.
I don't think it would. Typically both rich and poor communities would only be enforcing the FDA ceiling on lithium levels, which seems to be high enough that remediation is rarely (ever?) necessary, so rich/poor wouldn't correlate with levels much if all. The confounds which have come up as particularly plausible tend to deal with locations of mental hospitals, urban vs rural, and local food consumption.