Lithium, like lead, is an element, not a drug. And lithium, like lead, has a significant environmental impact on the general population -- specifically, on behavior. And the current lack of lithium in our environment is detrimental to us, and not what we evolved for, just as the past prevalence of lead within our environment was.
> And the current lack of lithium in our environment is detrimental to us, and not what we evolved for, just as the past prevalence of lead within our environment was.