David A. Clark, PhD, is Professor of Psychology at the University of New Brunswick, Canada. He has published seven books, including Intrusive Thoughts in Clinical Disorders: Theory, Research, and Treatment; Cognitive-Behavioral Therapy for OCD; and Scientific Foundations of Cognitive Theory and Therapy of Depression, as well as over 100 articles and chapters on various aspects of cognitive theory and therapy of depression and anxiety disorders. Dr. Clark is a Fellow of the Canadian Psychological Association, a Founding Fellow of the Academy of Cognitive and Behavioral Therapies, and a recipient of the Academy’s Aaron T. Beck Award for significant and enduring contributions to cognitive therapy. He is an Associate Editor of the International Journal of Cognitive Therapy and maintains a private practice.

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Aaron T. Beck, MD, until his death in 2021, was Professor Emeritus of Psychiatry at the University of Pennsylvania and President Emeritus of the Beck Institute for Cognitive Behavior Therapy. Internationally recognized as the founder of cognitive therapy, Dr. Beck has been credited with shaping the face of American psychiatry and was cited by American Psychologist as “one of the five most influential psychotherapists of all time.” Dr. Beck was 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 authored or edited numerous books for professionals and the general public.

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