what you describe is a pattern of alcohol abuse...a cycle....and in the time you've known him he's going round on his third cycle.
drink. then drink alot. mess everything up. sober up. clean up. straighten thngs out and get them back on track.
drink.
you get the idea.
it is not normal to keep your empties in your bedroom on the floor!
he's drinking to solve his depression problems, which is like shooting yourself in the foot to cure a hangnail. he has issues besides JUST the drinking, but unless HE is willing to look at those core issues and take proactive healthy measures to resolve them, he's going to keep spinning round and round on this cycle.
and things will get worse. he's a ticking time bomb. and i'd suggest not sitting next to said bomb while you wait for it blow.