[Faraone SV] Departments of Psychiatry and Neuroscience and Physiology, Psychiatry Research Division, SUNY Upstate Medical University, Syracuse, NY, USA. World Federation of ADHD, Switzerland. American Professional Society of ADHD and Related Disorders (APSARD), USA. [Banaschewski T] Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany. Child and Adolescent Psychiatrist's Representative, Zentrales-ADHS-Netz, Germany. The German Association of Child and Adolescent Psychiatry and Psychotherapy, Germany. [Coghill D] Departments of Paediatrics and Psychiatry, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia. [Zheng Y] Beijing Anding Hospital, Capital Medical University, Beijing, China. The National Clinical Research Center for Mental Disorders, Beijing, China. Beijing Key Laboratory of Mental Disorders, Beijing, China. Beijing Institute for Brain Disorders, Beijing, China. Asian Federation of ADHD, China. Chinese Society of Child and Adolescent Psychiatry, China. [Biederman J] Clinical & Research Programs in Pediatric Psychopharmacology & Adult ADHD, Massachusetts General Hospital, Boston, MA, USA. Department of Psychiatry, Harvard Medical School, Boston, MA, USA. [Bellgrove MA] Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Clayton, VIC, Australia. Australian ADHD Professionals Association (AADPA), Australia. [Ramos-Quiroga JA] Servei de Psiquiatria, Vall d’Hebron Hospital Universitari, Barcelona, Spain. Grup de Recerca en Psiquiatria, Salut Mental i Addiccions, Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain. Biomedical Network Research Centre on Mental Health (CIBERSAM), Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain. Departament de Psiquiatria i Medicina Forense, Universitat Autònoma de Barcelona, Bellaterra, Spain. Neurodevelopmental Disorders Across Lifespan Section of European Psychiatric Association, France. International Collaboration on ADHD and Substance Abuse (ICASA), the Netherlands. DIVA Foundation, the Netherlands