For example I know one man, who is professional driver and who loves drink a lot. In now days he can control if he drinks before work or in free time, but when he drinks, he can't control anything. He could has a bad decision, slow way of make decisions and he can be very dangerous for other people and for him selves. He has bed behavior in his drunker time. He is very vulgar and impolite.
Alcoholism is caused all groups of people.
Poor people usually drink because of their miserable life. Rich people drink, because they have enough money and they don't know what they should do with free time. And teenagers, I think, usually drink for the entertainment and for wish being more independent and feel like an adult. And other things can call out alcoholism. But it always depends on people.