I've read that it is hereditary. Both my parents were alcoholic & one of my brothers became an alcoholic (now sober for many years); my other brother has never taken a drink in his life due to seeing what devastation alcohol can do; I've had my times of excessive drinking. I drink moderately now--some days none--some days a few glasses of wine, but in my past I drank til I blacked out (due to untreated bp?)--Suzy