David A. Clark, PhD, is a clinical psychologist and professor emeritus at the University of New Brunswick. 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.Robert L. Leahy, PhD, is author or editor of twenty-seven books, including The Worry Cure, The Jealousy Cure, and Beat the Blues. He is director of the American Institute for Cognitive Therapy in New York, NY, and clinical professor of psychology at Weill Cornell Medical College. Leahy has been featured in The New York Times, The Wall Street Journal, and more.