E. Morton Jellinek was a biostatistician, physiologist, and an alcoholism researcher. He lived between 1890 and 1963. Perhaps one of the most famous things that Jellinek did was assign Greek letters of the alphabet to the stages of alcoholism. He broke the stages of alcoholism down into five majors stages and labeled them with letters of the Greek alphabet. Alpha alcoholism is the earliest stage and describes a person who is a problem drinker.
Beta alcoholism refers to someone who is a heavy drinker drinking almost everyday but without physical dependence. Gamma alcoholism refers to someone with physical dependence and loss of control. Delta alcoholism is much like Gamma but involves an inability to abstain and Epsilon alcoholism is the most advanced stage.