Jeffrey D. Roth is Editor of the Journal of Groups in Addiction and Recovery and the author of Group Psychotherapy and Recovery from Addiction: Carrying the Message. He is the medical director of Working Sobriety Chicago, an outpatient treatment program for addiction. William L. White is a Senior Research Consultant at Chestnut Health Systems in the USA. John F. Kelly is Associate Professor in Psychiatry at Harvard Medical School, USA, Program Director of the Addiction Recovery Management Service and Associate Director of the Center for Addiction Medicine in the Department of Psychiatry at the Massachusetts General Hospital in Boston, USA.