It's extremely common for those with anxiety and depression issues to abuse alcohol. I read that something like up to 40% of people with the conditions have abused alcohol to some level. Mostly coming down to alcohol working in a similar way to many mental health prescription medications.
I dealt with severe anxiety issues for years, and once I found alcohol, I thought I found "it", the miracle cure to my issues. And it did work, in fact it worked too well that it drove me into full blown alcoholism, turning my "cure" into a complete nightmare making my anxiety and depression a million times worse.