David R. Gastfriend, M.D., is Director of the Addiction Research Program at Massachusetts General Hospital (MGH) and Associate Professor of Psychiatry at Harvard Medical School. He founded the Fellowship in Addiction Psychiatry at MGH and continues to teach and provide outpatient substance abuse clinical care at MGH. He is one of the few physicians in the country to be certified both in Addiction Medicine by the American Society of Addiction Medicine and in Addiction Psychiatry by the American Board of Neurology and Psychiatry.

Dr. Gastfriend discusses the progress of scientific research of addiction. Defining the components of America's drug abuse epidemic, Dr. Gastfriend highlights the relationships between access to drugs, social reinforcement of drug abuse, and the variety of drugs that are abused.