William R. Miller, PhD, is Emeritus Distinguished Professor of Psychology and Psychiatry at the University of New Mexico. He introduced motivational interviewing in a 1983 article and in the first edition of Motivational Interviewing (1991), coauthored with Stephen Rollnick. Dr. Miller’s research has focused particularly on the treatment and prevention of addictions and more broadly on the psychology of change. He is a recipient of two career achievement awards from the American Psychological Association, the international Jellinek Memorial Award, and an Innovators Award from the Robert Wood Johnson Foundation, among many other honors. His publications include 65 books and over 400 articles and chapters. His website is https://williamrmiller.net. Ricardo F. Muñoz, PhD, is Distinguished Professor of Clinical Psychology at Palo Alto University and Emeritus Professor of Psychology at the University of California, San Francisco. His major areas of expertise include addictive behavior, the prevention and treatment of depression, and how depression affects substance use. He has published over 100 scientific articles and chapters and several books, including Control Your Depression and The Prevention of Depression.