There's a person I have known since he was about six. He's now a young adult. He is a sociopath. He's got that dead sociopathic look in his eyes and does things with no conscious, completely self centered. Sometimes he looks at you and chills go down your back. Sometimes you just look in his eyes and know he's thinking about killing you. He's creepy and scary at times, by doing nothing, just how he looks. But he also has that sociopathic charm--he seems shy and confiding and sweet. It's easy to get sucked in.
He also has schizophrenia, although it hasn't really taken hold yet. He's had short episode of hearing voices and hallucinating since about age 11. His mother, grandfather and three uncles were schizophrenic. Their variety doesn't really take hold until about age 30, and then when it does, it's the kind that really can't be controlled with known medication. It destroys their lives. Every once in a while you can see the scared crazy look in his face, the deer in the headlight look, the my inner reality isn't matching up with the world reality look. It doesn't happen often, but when it does, you feel very sorry for him.
Recently he's taken up drinking. He's goofy and vulnerable mostly when he drinks, although I understand he can be bitter and self pitying. I haven't seen him drinking, but he's a distant family member and I hear about it. There's alcoholism in the other side of his family.
This kid never had a chance at a decent life. I look at him and wonder what's going to win out: the sociopathy? The schizophrenia? The alcoholism? What's going to manifest the strongest. Will the schizophrenia knock out the sociopathy? How will the alcoholism play into it? The drinking is a recent thing.
He has a vodka drinking very passive whiny alcoholic father, a sister who was raised from infancy to be codependent, a mother in and out of mental institutions and who wanders the streets in psychosis much of the year, and a crazy personality disordered dependent whiny passive aggressive controlling enmeshed grandmother. They are all in denial of all of their problems, most especially his (he's just a genius that's all).
When you say alcohol is just a symptom, I think of this kid (actually he's now a young adult). The drinking is all anyone ever focuses on, although they are trying to play it off as youthful experimenting. Yeah, he got a DUI, but THAT's NOT REALLY THE PROBLEM!!