David A. Clark, PhD, is Professor Emeritus with the Department of Psychology, University of New Brunswick, where for 26 years he taught, conducted research and trained dozens of graduate students in clinical psychology. For over a decade he was Director of the Clinical Training Program, providing leadership in the development and eventual accreditation of our doctoral program in clinical psychology. After receiving a PhD in psychology from the Institute of Psychiatry, University of London, UK in 1984, he obtained further training in cognitive therapy under Aaron T. Beck, MD. Over the past 30 years he has trained dozens of students in cognitive behavior therapy and offered clinical skills workshops to hundreds of mental health professional worldwide.

He is author or coauthor of several books on depression, anxiety, and obsessive-compulsive disorder (OCD), including The Anxiety and Worry Workbook with Aaron T. Beck (founder of cognitive therapy), The Anxious Thoughts Workbook, and Cognitive-Behavioral Therapy for OCD and Its Subtypes. Clark is a founding fellow and trainer consultant with the Academy of Cognitive and Behavioral Therapies, and fellow of the Canadian Psychological Association. He is author of the blog, The Runaway Mind, on www.psychologytoday.com.