My AH was just a social drinker the first 10 years we were together; he'd have the occasional beer or glass of wine and it was no problem. The second 10 years has been a slow spiral into more and more drinking. About 7-8 years ago I realized there was a problem, and the last 2 years have been a living hell. We are now separated.
Looking back, though, some of the personality issues that have been really magnified by his alcoholism were there all along. Low self esteem and self confidence as well as serious lack of emotional intimacy.