IA about Matt--and also, I think Matt is just fundamentally a control freak. He works his issues out by beating the shit out of people; the only time we really see him drunk is in that one flashback, where he's (a) happy and (b) in the company of someone he trusts. I don't think he'd be willing to drink heavily in any other circumstances, both because he doesn't trust other people and because he doesn't really trust himself. He's very aware of the kind of violence he's capable of, you know?

I do think some of it's probably physical, but I think a lot of it is just his personality. Foggy doesn't really have the same issues--which is not to say he doesn't have issues, just that they're different ones.