David A. Clark, PhD

David A. Clark, PhD, is a clinical psychologist and Professor Emeritus at the University of New Brunswick, Canada. He is author of several books on depression and anxiety, including Overcoming Obsessive Thoughts, The Anxiety and Worry Workbook, The Anxious Thoughts Workbook, and The Negative Thoughts Workbook. He has coauthored several books with the pioneer of cognitive behavior therapy, Aaron T. Beck.