Do insane people use run on sentences?

I've been thinking about mental illness. Y'know, for the city, where there's an asylum on every block. I mean, it is going  to be some sort of made up insanity, but is there a disease I should work from? I don't want to seem like I'm grossly exaggerating or making fun of a serious mental illness. 

Y'know, I've been thinking I won't even write anything that goes on in the "madhouses". They could just be these... buildings. People go in, but nobody comes out. People won't be, like, killed in there. It's just some sort of prison. But nobody outside is sure. I think they'd be... creepier that way. 

Okay, I should probably be paying attention right now. I will consider this more later.