L. Jarrett Barnhill, MD is Professor of Psychiatry at The University of North Carolina School of Medicine. He was the Director of the Developmental Neuropharmacology Clinic within the Department of Psychiatry. He is a Distinguished Fellow in the American Psychiatric Association and Fellow in the American Academy of Child and Adolescent Psychiatry. His clinical interests include autism and other developmental disorders, traumatic brain injury, neuropsychiatry of mood and seizure disorders, and Tourette’s disorder and other movement disorders. Dr. Barnhill is a Co-Editor of the DM-ID-2. Professor Sally-Ann Cooper was appointed to the University of Glasgow in 1999 to its foundation Chair of Learning Disabilities, and established the Glasgow University Centre of Excellence in Developmental Disabilities. She is Deputy Head of the Institute of Health and Wellbeing and also works as an Honorary Consultant Psychiatrist within NHS Greater Glasgow and Clyde. She has published extensively on the epidemiology of health and health inequalities in adults with intellectual disabilities, and trials of complex interventions to improve their health. Professor Cooper is Director of the Scottish Learning Disabilities Observatory, funded by the Scottish Government. Established in 2015, it is focussed on contributing to a fairer and healthier Scotland through raising awareness of and providing evidence-based solutions to the health inequalities people with intellectual disabilities experience, monitoring and assessing health trends, and translating this into useful intelligence for policy development, use by practitioners, service comissioners, and people with intellectual disabilities and their carers. Her current grants also include trials, such as a randomized controlled trial of behavioural activation for adults with intellectual disabilities. She currently leads a team including five post-doctoral and six post-graduate researchers. She is the mental health editor of the Journal of Intellectual Disabilities Research, and is currently Chairing the NICE Guideline Development Group on mental ill-health and people with intellectual disabilities. Dr. Robert Fletcher is the Founder and Chief Executive Officer of the NADD. His vision and leadership have brought NADD to a position where it is recognized as the world’s leading organization in providing educational resources, conferences, trainings, consultation services, as well as accreditation and certification programs in the field of dual diagnosis. For the last forty years, Dr. Fletcher has dedicated his professional career to improving the lives of individuals who have a dual diagnosis (IDD/MI). He has been involved as a clinician, program developer, policy maker, researcher and consultant. He has authored or co-authored numerous articles and has written or edited 10 books addressing mental health aspects in persons with IDD, including Chief Editor of the Diagnostic Manual – Intellectual Disabilities (DM-ID) and Psychotherapy for Individuals with Intellectual Disability. In recent years, Dr. Fletcher has spearheaded the NADD Accreditation and Certification Programs in an effort to raise the bar for provision of services to individuals with IDD/MI.