Carlo C. DiClemente, PhD, ABPP, is Emeritus Professor of Psychology at the University of Maryland, Baltimore County. He is codeveloper of the transtheoretical model of behavior change, used by researchers and clinicians internationally. Dr. DiClemente's contributions have been recognized with awards from the Robert Wood Johnson Foundation, the American Society of Addiction Medicine, the Association for Behavioral and Cognitive Therapies, and the American Psychological Association. Most recently, he was invited to deliver the Jack Mendelson Honorary Lecture at the National Institute on Alcohol Abuse and Alcoholism and received a Lifetime Achievement Award from the National Register of Health Services Psychologists. Dr. DiClemente has authored or coauthored over 250 articles, book chapters, and books on motivation and behavior change.

Mary Marden Velasquez, PhD, is Centennial Professor in Leadership for Community, Professional, and Corporate Excellence and Director of the Health Behavior Research and Training Institute at The University of Texas at Austin (UT Austin) School of Social Work. She also holds appointments in the Department of Population Health and the Department of Psychiatry and Behavioral Sciences at UT Austin's Dell Medical School. A Distinguished Fellow of the American Academy of Social Work and Social Welfare, Dr. Velasquez is a recipient of the Betty Ford Award from the Association for Multidisciplinary Education and Research in Substance use and Addiction and the Charles C. Shepard Science Award from the Centers for Disease Control and Prevention, and a founding member of the Motivational Interviewing Network of Trainers.