Each person's "history" with alcohol is different. Many started out drinking socially only but didn't become addicted at first. Then, some may turn to alcohol to ease stress, relieve tension, "feel good", cut loose,whatever....you get the picture. But if people keep drinking and drinking more and more and more frequently, it turns into a dependence and they feel they can't live without it and they absolutely HAVE to have it in various situations and even on a daily basis. I remember during my college years one of my sisters said she could not get out of a dance for and dance unless she had guzzled 3-4 beers first. And I thought, why can't a person just dance without it? I always could .It's like it then became what they primarily used to "feel good". Myself, it's always been faith, fitness and music as my "go to". But I got into some trouble with depression later in life that threw me for a loop and that was a game changer for me. I needed help for my depression and finally got it and got better, but not until I tried alcohol to help, which by the way....is the WORST antidepressant on the market. I know people have used it medicinally for ages, but it doesn't help depression.
In answer to your question, yes, I think many people self medicate with alcohol.