Richard P. Swinson, MD, is Professor and Chair of the Department of Psychiatry, Faculty of Health Sciences, McMaster University. He is also Professor in the Department of Psychiatry at the University of Toronto, and Psychiatrist in Chief at St. Joseph's Hospital and Hamilton Psychiatric Hospital in Hamilton, Ontario. Previously, he held several appointments at the Clarke Institute of Psychiatry, including Vice President Medical Affairs, Chief of Medical Staff, and Head of the Anxiety Disorders Clinic. Dr. Swinson is currently chair of the Examination Board in Psychiatry for the Royal College of Physicians and Surgeons in Canada. He has published approximately 200 scientific papers, book chapters, and reports, mostly on anxiety disorders and related conditions. In addition, he was a member of the DSM-IV subcommittees for obsessive-compulsive disorder and for panic disorder and agoraphobia.

Martin M. Antony, PhD, is Chief Psychologist and Director of the Centre for the Study of Anxiety at St. Joseph's Hospital in Hamilton, Ontario. He is also on faculty in the Department of Psychiatry at Ryerson University. Previously, Dr. Antony was Assistant Professor in the Department of Psychiatry, University of Toronto, and staff psychologist in the Anxiety Disorders Clinic, Clarke Institute of Psychiatry. He received his Ph.D. in clinical psychology from the State University of New York at Albany in 1994 and completed his predoctoral internship training at the University of Mississippi Medical Center in Jackson. Dr. Antony has written several books, including Mastery of Your Specific Phobia (and the accompanying therapist manual), with Michelle G. Craske and David H. Barlow, as well as numerous research papers and book chapters in the areas of obsessive-compulsive disorder, panic disorder, social phobia, and specific phobias. He is actively involved in clinical research in the area of anxiety disorders, teaching and education, and maintains a clinical practice.

S. Rachman, PhD, is currently Professor of Psychology at the University of British Columbia in Vancouver, British Columbia, and was formerly Professor of Abnormal Psychology at the Institute of Psychiatry, University of London. He is an active clinician and researcher and has published extensively on the subjects of fear, anxiety, anxiety disorders, and obsessive-compulsive disorder. He has written or edited more than 15 books and monographs and many additional journal articles and book chapters. In 1980, along with R. Hodgson, Dr. Rachman published Obsessions and Compulsions . In 1992, he published a guide for patients and their families called Obsessive Compulsive Disorders with P. de Silva. His book, Fear and Courage , was published in a second edition in 1990. Dr. Rachman received a Distinguished Scientist Award from the American Psychological Association (Division 12) in 1984 and was made a fellow of the Royal Society of Canada in 1989.

Margaret A. Richter, MD, received her M.D. from the University of Ottawa and completed her psychiatric training at the University of Toronto. She was named the Mary Early Fellow by the Canadian Psychiatric Research Foundation from 1990-1992 for her work on the familial nature of OCD. Currently, she is Assistant Professor in the Department of Psychiatry, University of Toronto, and Staff Psychiatrist in the Anxiety Disorders Clinic, Clarke Institute of Psychiatry. She continues to be actively involved as a clinician and research in the area of OCD, particularly with respect to the genetic basis of OCD and the relationship between OCD and spectrum disorders.