As a recovering alcoholic, I could go on and on about the standard AA language and stuff, but I don't believe that people who drink to excess occasionally are alcoholics...So I will get that out of the way.
I will say, that alcohol to excess has MAJOR potential to trigger a hypo/manic or depressive episode.
For a while I attended meetings to help me get through the first part of quitting drinking...for like 6 months I did meetings maybe. But eventually I came to realize that drinking for me was really a way to deal with my varying mental states....and when I started to accept them and treat them appropriately, I no longer needed to drink to handle or mask them.
I don't drink at all any more, because in 'self-medicating' in the past, I developed alcoholism and know that one would turn into a dozen....and not just for the one night...but every night until I hit bottom again...or had a major episode..whichever can first.
Just my two cents....
If you can handle an occasional drunk without too much fallout...then do it...and enjoy....if drinking comes with so much fallout that you it impacts your moods and you don't want that to happen, then stop....period.