I think a lot of people use alcohol to self medicate other underlying issues. I think it would be very hard for a truly healthy person to stay alcoholic. A person with self introspection (versus self centeredness), is able to see that they have a problem and is able to find help/solutions. A truly mentally ill person is not capable of seeing themselves in a realistic fashion. I think healthy people can get addicted to alcohol, but I think it is easier for a healthier person to kick the habit.