This thread has been very enlightening in a lot of ways. There seem to be people out there who due to a combination of personality and circumstance can find themselves dragged into an addiction that they never would have thought themselves capable of. A lot of the time there seems to be a certain amount of denial there, though.
I suspect my step-mum is an alcoholic, but she denies it vehemently. She functions throughout the working day, but there will be times when I've caught her drinking on her own and out of concealed cans of coke. She drinks with my dad a lot on their days off, and there's nothing wrong with that but they've always seemed like 'drinking buddies' to me more than man and wife. Which is quite an upsetting state of affairs to be honest. We have confronted her about it, but she blames a lot of the side effects we point out (such as memory loss) on the menopause, which y'know, could very well be true but it's difficult to pin her down because we have no solid evidence of exactly how much she's drinking. We say we want to help but she really doesn't think she needs it. She's quite an intelligent woman by all means, but I notice so much strange behaviour coming from her I can't help but worry.
Being a step-son though, not even directly related, makes it difficult for me to assert anything because there are other people before me (my dad for one) who should be bringing up the elephant in the room but they're not. That gives her some kind of justification as my words only carry weight if they're backed up by the people closest too her. Talking out of turn comes to mind.
As for myself, I'm in the same boat as a few others on this thread, I drink socially but I really do it out of convention rather than desire. I could quite easily wake up tomorrow and decide to be teetotal, I only drink every other week so it would probably just save me money in the long run.