
Russell A. Barkley (born 1949) is a clinical psychologist who is a clinical professor of psychiatry at the Medical University of South Carolina and an author of books on ADHD. Involved in research since 1973 and a licensed psychologist since 1977, he is an expert on attention-deficit hyperactivity disorder (ADHD) and has devoted much of his scientific career to studying ADHD and related problems in children. His research interests include childhood defiance.