Nancy Cain, MD, is an expert in the field of dual diagnosis for many years, presented at national and international meetings, and done clinical research on aggression, crisis intervention, and bipolar disorder in individuals with intellectual disability. Geraldine Holt, MBBS, BSc, FRC Psych, is a consultant psychiatrist in learning disabililties at South London and the Maudsley NHS Trust, and honorary senior lecturer at the Institute of Psychiatry in London, England. She is also a fellow of the Royal College of Psychiatrists. Phillip W. Davidson, PhD, is a professor of pediatrics and psychiatry at the University of Rochester School of Medicine and Dentistry, and the director of the Strong Center for Developmental Disabilities. He is the author of more than 100 peer-reviewed publications. Nick Bouras, MD, PhD, FRC Psych, is a professor of psychiatry at the Institute of Psychiatry at King's College in London, and is a consultant psychiatrist at South London, England and the Maudsley NHS Trust.