@Pangloss,
I guess that depends on how you define alcoholic. I'm a college student, and most nights I can be found with a beer in my hand. Does that make me an alcoholic?
If Bush says he was an alcoholic, how much of that claim is based on his recently developed world view? He is an extremely, fundamentalist Christian. Super-original sin and all that. No sex before marriage. All kinds of crazy ideas.
I wouldn't doubt that he has some permanent liver damage, but I'm skeptical that his drug use caused significant damage to his cognitive capacity. Remember, this is a guy who made it to the White House, not by his own brilliance, but because he surrounded himself with greedy, and clearly intelligent individuals. They invented Bush's Presidency. That's one of his great legacies - his subservience to advisers. He has a unique inability to lead.