Aaron T. Beck, MD, is the founder of cognitive therapy, University Professor Emeritus of Psychiatry at the University of Pennsylvania, and President Emeritus of the Beck Institute for Cognitive Behavior Therapy. Dr. Beck is the recipient of awards including the Albert Lasker Clinical Medical Research Award, the Lifetime Achievement Award from the American Psychological Association, the Distinguished Service Award from the American Psychiatric Association, the James McKeen Cattell Fellow Award in Applied Psychology from the Association for Psychological Science, and the Sarnat International Prize in Mental Health and Gustav O. Lienhard Award from the Institute of Medicine. He is author or editor of numerous books for professionals and the general public. A. John Rush, MD, is Professor Emeritus at Duke–NUS Medical School, National University of Singapore, and Adjunct Professor in the Department of Psychiatry and Behavioral Sciences at Duke Medical School. His research has focused on the diagnosis and psychotherapeutic, psychopharmacological, and somatic treatment of depression and other mood disorders. Dr. Rush's internationally recognized work has received numerous awards. Brian F. Shaw, PhD, is a Professor in the Departments of Psychiatry and Public Health Sciences at the University of Toronto, and a member of the graduate faculty in the Institute of Medical Science, University of Toronto. Gary Emery, PhD, is director of the Los Angeles Center for Cognitive Therapy and Assistant Clinical Professor in the Department of Psychiatry at UCLA.