People change when drunk…or not?

I (40M) have a (slightly more than) friend (34M) who gets crazy when he’s drunk. I know he has a drinking problem, no lie about that. But I listen to the pain, confusion, panic, anger, isolation, and loneliness he expresses and it utterly breaks my heart. I never asked him if he remembers afterwards, and he never brings it up. He’s his normal self again. I was wondering if his drunken monologue was a reflection of real struggles inside, or a crazy mixed-up altered state induced by substance abuse, basically?