I'd look to alcohol first. It's been legal for much more of the modern age, and certainly also carries with it the risk of psychosis. And as the other comment

I'd look to alcohol first. It's been legal for much more of the modern age, and certainly also carries with it the risk of psychosis. And as the other commenter points out, "Whither Meth?" Probably all of these things are contributing factors, in some form.