A lot of people don't understand that alcohol creates significant depression and anxiety, even if you weren't anxious or depressed beforehand.
Whether alcohol is creating symptoms like that, or adding to the problems you have, it's often tempting to seek temporary relief by drinking these feelings away - in the short term. Then you can get into a vicious cycle of doing more of the thing that's damaging you.
If you have a more severe mental health problem - of whatever variety - then you can be certain that drinking will never ever do anything to make it better. It will only ever make it worse
The reason a lot of people feel trapped by drinking is that whilst stopping drinking can make you feel much much better mentally - this takes a while to happen.