David A. Clark is Professor Emeritus with the Department of Psychology, University of New Brunswick Fredericton, where for 26 years he taught, conducted research and trained dozens of graduate students 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.  He has published over 150 scientific articles and papers on cognitive theory and therapy of depression and anxiety disorders with funding obtained from the Social Sciences and Humanities Research Council of Canada, Canadian Institutes of Health Research, and the Foundation for Cognitive Therapy. He has coauthored several peer-reviewed papers and books with Dr. Beck including “Scientific Foundations of Cognitive Theory and Therapy of Depression” (Wiley, 1999), Cognitive Therapy for Anxiety Disorders (Guilford, 2010), and The Anxiety and Worry Workbook (Guilford, 2012), as well as single authored works such as Cognitive Behavioral Therapy for OCD (Guilford, 2004) and The Mood Repair Toolkit (Guilford, 2014).  He continues to offer training workshops worldwide and maintains a part-time private practice. He is a Founding Fellow and trainer/consultant with the Academy of Cognitive Therapy, a supervisor with the Beck Institute, Fellow of the Canadian Psychological Association, and recipient of the Aaron T. Beck Award for Significant and Enduring Contributions to Cognitive Therapy in 2008.  He is currently writing a workbook for New Harbinger Publications and Little Brown UK entitled Controlling Your Mind: A Workbook for Anxiety, Depression and Obsessions.