Did he actually paint those? Although they are weird, first one is very grusome, it's weird how such talent is lost in the depths of such madness. 
yeah, those are his. i saw the top one in a museum, it's enormous.
i don't think the talent was lost, i think it was a function of his madness. seems like all the best artists have something "wrong" in their brains. but it's hard to call it wrong when it produces things like that.