Charles P. O´Brien, a native of New Orleans, earned his M.D. and Ph.D. degrees from Tulane University. He received residency training at Harvard, Tulane, University of London, and University of Pennsylvania in internal medicine, neurology and psychiatry. As Chief of Psychiatry at the Philadelphia VA Medical Center, he was responsible for over 9,000 psychiatric patients. Despite this large clinical responsibility, he was able to establish and direct a clinical research program that has had a major impact on the treatment of addictive disorders. His research group has been responsible for numerous discoveries described in over 400 publications that have elucidated basic information on the nature of addiction and improved the results of treatment for addictive disorders. This includes new medications, behavioral treatments and instruments for measuring the severity of addictive disorders. He was elected to the Institute of Medicine of the National Academy of Sciences in 1991, and he has received numerous national research awards as well as an honorary doctorate from the University of Bordeaux in 1994. Dr. O´ Brien is a past- president of the American College of Neuropsychopharmacology and the Association for Research in Nervous and Mental Disease. Currently he is the Kenneth Appel Professor, Vice-Chair of Psychiatry at the University of Pennsylvania, Director of the Center for Studies of Addiction and founder of the Charles O'Brien Center for Addiction Treatment.