Steve Sussman received his doctorate in psychology from the Univeristy of Illinois at Chicago. He is now a professor at the Institute for Health Promotion and Disease Prevention Research at the University of Southern California. He has published over 160 articles in the areas of drug abuse prevention and cessation, and empirical programme development. Particular research interests include psychosocial prediction of tobacco and other drug use, and drug abuse prevention and cessation. Susan L. Ames earned her doctorate in health behaviour research from the Department of Preventive Medicine at the University of Southern California. She is a part-time staff research associate at the Center for Research on Substance Abuse at the University of California, Los Angeles and part-time research associate at the Institute for Health Promotion and Disease Prevention Research at the University of Southern California. Her research interests include the impact of memory on addictive behaviours, developing prediction models of substance use, prevention and harm reduction of addictive behaviours, and the psychosocial correlates of drug use.