Arnold M. Washton, PhD, is a psychologist in private practice in New York and New Jersey, specializing in the treatment of substance use and other behavioral health problems since 1975. Dr. Washton has served as Clinical Professor of Psychiatry at New York University School of Medicine, as director of several nationally recognized addiction treatment and research programs, and as consultant to professional sports teams, government agencies, media organizations, and major corporations. He has served on the Substance Abuse Advisory Committee of the U.S. Food and Drug Administration and has given expert testimony before special committees of the U.S. Senate and House of Representatives on drug abuse trends in the United States. The author of several books and numerous journal articles on addiction and its treatment, Dr. Washton has devoted most of his career to developing individualized approaches to treating addiction that incorporate the principles and practice of client-centered psychotherapy. His website is www.thewashtongroup.com.

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Joan E. Zweben, PhD, is an addiction psychologist who began treating co-occurring psychiatric and addictive disorders, and training treatment practitioners, in the 1970s. She has a broad-based background in mental health, alcoholism, and drug dependence, and has experience with both residential and outpatient modalities. Dr. Zweben has a long-standing commitment to building treatment resources through networking activities, and to addressing stigma in its many forms. She is the founder and retired executive director of two treatment programs providing integrated services for people with co-occurring disorders: The 14th Street Clinic (opioid treatment) and East Bay Community Recovery Project (now part of Lifelong Medical Care), both in Oakland, California. Active as a teacher and consultant, Dr. Zweben is Clinical Professor of Psychiatry at the University of California, San Francisco, based at the San Francisco VA Medical Center. Her publications include four books, over 90 articles or book chapters, and 15 monographs on treating addiction.