I was diagnosed by a psychiatrist with depression years ago before I was much of a drinker. Towards the end of my drinking, the depression and anxiety were unbearable. That is what finally drove me to quit. After I got sober, the depression lifted almost as if by magic.
I still deal with my mental health issues, but I can actually deal with them in a healthy way now, in a way that actually works, instead of making things so much worse by drinking.