Everyone is different and there's a lot of factors in play for each case. I can speak for myself though and say it's very much a self-medicating exercise that slowly gets out of control until you can't cope without alcohol anymore because you become so dependant on it to "feel better."

Of course you don't really feel better in the long run, you feel much much worse.

It was a cheaper and less confrontstial alternative to seeing a professional to try and deal with some mental health issues that have plagued me for well over a decade (anxiety, depression, etc.). I'm very high functioning and I can go about my day to day life but I've still been drunk almost every night for close to three years now, and it's gotten to the point where I've realised I really have to force myself to make a change if I want to become a better person for me and the people I love.

That's just a bit of my thoughts on it though, I hope that sheds some light on the subject for you (: