Most alcoholism cases begin when the alcoholic takes his/her first drink. That usually occurs in the early teenage years so that the psychological effects of addiction are already in place when the "what am I going to do with my life?" choices are being made.
From the onset alcohol addiction causes ego inflation and people with bloated egos are more likely to select professions that offer the prospect of big ego payoffs. Thus the high percentage of alcoholic writers and actors.
James Graham, Author of "Vessels of Rage, Engines of Power: The Secret History of Alcoholism."