Let's not forget that his doctor kept injecting him with a meth cocktail. I think that's what sealed the deal.
Anyways, I stand by what I said about one man's sane. If you look hard enough, you can find some mental problem in everyone. No one is truly sane, for sane never worked for anyone. It's the other way around: Everyone works for sane.
It's much easier to be crazy. More happiness that way.