Regarding Willie-O's mention of "controlled drinking", and his earlier reference to "controversy about...whether problem drinkers or alcoholics can ever become moderate social drinkers again," my understanding is there is a distinction between alcohol abusers (problem drinkers) and alcoholics.

Alcoholics have a physiological handicap, they are physically incapable of stopping at one drink (this trait seems to be at least partially hereditary). They can never become social drinkers, it's essentially all or nothing. Moderate drinking is not possible for them.

Alcohol abusers, on the other hand, are theoretically capable of using alcohol in moderation. Whether any given individual can accomplish this depends on various factors, and many are wise not to tempt fate, but it is within the realm of possibility.

How one reliably determines the difference between the two situations I don't know, other than trial and error.