Help needed: My friend thinks he has a serious drinking problem?!

I've been friends with my buddy Ron since high school. We've always partied together and over the past few years we drink on a nightly basis (or, at least, whenever we chill together).

Ever since his DUI, Ron has been telling me he has a drinking problem. Apparently he got wasted and blew his $2,000 Christmas bonus at the casino last month. He also recently broke up with his girlfriend and may also lose his job because he's been sleeping with his boss. He's also been having serious stomach problems, which he blames on whiskey.

With all this stuff going on he's gotten real depressed and keeps talking about how he needs to "make a change". I'm starting to get seriously worried, since my other buddies tell me he hasn't been drinking, except for around me (probably since he thinks of me as a big brother). I even found an AA pendant in his house, but he says that he legally HAD TO go to class because of the DUI. I asked him if he drank before the class, and he said "Yeah," but I'm not really sure if I believe him.

Anyway, I had a party this weekend and Ron didn't drink ANY whiskey at all! I had to make sure he played beer-pong and card games with everyone in order to make sure he got trashed. But then he got upset because he crashed his mom's car on the way home when I told him he couldn't stay the night.

I'm really concerned about my friend. How do I convince him he doesn't have a drinking problem?