Russell A. Barkley, PhD, ABPP, ABCN, is Clinical Professor of Psychiatry and Pediatrics at the Medical University of South Carolina. Dr. Barkley has published numerous books and five assessment scales, plus more than 275 scientific articles and book chapters on ADHD, executive functioning, and childhood defiance. He is also the editor of the newsletter The ADHD Report. A frequent conference presenter and speaker who is widely cited in the national media, he is past president of the Section on Clinical Child Psychology of the American Psychological Association (APA) and of the International Society for Research in Child and Adolescent Psychopathology. He has received awards for his career contributions to research, clinical practice, and the dissemination of science from the American Association of Applied and Preventive Psychology, the American Academy of Pediatrics, the Society of Clinical Child and Adolescent Psychology (APA Division 53), and the Society for a Science of Clinical Psychology. His website is www.russellbarkley.org.