Jan van Niekerk, PhD, is a registered clinical psychologist practicing in Cambridge, United Kingdom. He is an associate at the Cambridge Clinical Research Centre for Affective Disorders and author of Coping with Obsessive-Compulsive Disorder.

Foreword writer Christine Purdon, PhD, CPsych, is associate professor of psychology at the University of Waterloo in Waterloo, ON, Canada; and consulting psychologist with the Anxiety Treatment and Research Clinic at St. Joseph’s Healthcare in Hamilton, ON, Canada.