" The major difference between heroin and alcohol is that, contrary to popular belief, heroin has no physically harmful effect. Alcohol is physically harmful to the brain, to the liver, to the nerve endings, eventually perhaps even to the stomach and intestines. Both drugs seem equally addicting, and why a person chooses one over another is probably based on experience, on availability, on legality, and on some personal idiosyncrasy not yet understood. What we do know is that the drugs work to relieve the pain and provide pleasure "

― William Glasser , Positive Addiction