I couldn't tell you for sure. That is certainly how it started for me, though.
I ask myself all the time, if it had not been for all those late nights partying it up at the clubs, would I be an alcoholic today?
I have heard of the term "functional alcoholic", though. People who meet the general medical definition of alcoholism, but seem to have pretty darn successful lives, in spite of it. (I'm think of quite a few of the politicians out there).