William C. Sanderson, Ph.D., is a professor of psychology and Director of the Doctoral Program in Clinical Psychology at Hofstra University, where he teaches and conducts research on the nature and treatment of anxiety disorders and depression, as well as evolutionary psychology. He also directs the Anxiety and Depression Clinic at Hofstra. Dr. Sanderson received his Ph.D. working under the mentorship of Dr. David Barlow at the Center for Stress and Anxiety Disorders at the University of Albany. He then completed a fellowship in Cognitive Therapy with Dr. Aaron T. Beck (the founder of cognitive therapy) at the Center for Cognitive Therapy, University of Pennsylvania. He has served on numerous national committees, including the American Psychiatric Association DSM-IV Anxiety Disorders Workgroup, served as editor of The Clinical Psychologist, and was the Chair of the American Psychological Association Division of Clinical Psychology's Committee on Science and Practice (a Task Force aimed at identifying and promoting the practice of evidence-based psychological interventions). Dr. Sanderson has published more than 100 articles and seven books primarily in the areas of anxiety, depression, evidence-based treatments, and cognitive behavior therapy.