Jon E. Grant, M.D., M.P.H., J.D., is Professor in the Department of Psychiatry at the University of Minnesota in Minneapolis, Minnesota. Dan J. Stein, M.D., Ph.D., is Professor in the Department of Psychiatry and Mental Health at the University of Cape Town in Cape Town, South Africa. Douglas Woods, Ph.D., is Professor in the Department of Psychology at the University of Wisconsin - Milwaukee in Milwaukee, Wisconsin. Nancy J. Keuthen, Ph.D., is Associate Professor of Psychology (Psychiatry) at Harvard Medical School; Co-Director of the Trichotillomania Clinic and Research Unit; and Chief Psychologist in the Obsessive Compulsive Disorder Clinic and Research Unit at Massachusetts General Hospital in Boston, Massachusetts.