I agree the evidence do not strictly prove that , but at least, in general , from all we know about indigenous populations , we have good evidence on how one type of society that's conductive to mental health should roughly look like.

And yes, even if mental illness is rooted in biology , we know that some environments cause it to manifest and some environments don't , and since we cannot change biology (and drugs are a very poor solution to such problems ) this means , at least that a big part of the solution is environmental change.