Twisted Words

So I have this friend. This really good friend. Most of you probably know him, actually. And I'm worried about him. Alot. He's been caught on the same girl for quite a while, convinced she's THE girl. I've never met her... but she treats him with such disrespect. She cheated on him. She ignored him. She didn't even say good-bye when she left him. And now she's found someone else. But he still loves her with all of his heart...

What do you say to someone like that? I want to help him, I really do. But for now it seams like the only thing I can do is pray... and watch him slowly spiral deeper and deeper into his depression. I at least want him to find a healthier way to cope with it instead of chain-smoking and drinking the pain away...
I've tried everything and now I just don't know what to try anymore...