While attention-deficit/hyperactivity disorder (ADHD) is sometimes portrayed as a "modern" condition, George Still (1902) is now credited with the first clinical description of what today would be recognized as ADHD. The first treatment of impulsive, hyperactive, and disruptive behavior with stimulant medication was reported in the 1930s (Bradley 1937). Virginia Douglas (Douglas and Peters 1979) first critically examined the psychological data emerging from the study of "hyperactive" children and laid out the cardinal symptoms of the disorder as inattention, impulsivity, and hyperactivity; it was further noted that a subset of children with "hyperactivity" were inattentive without being hyperactive. Such data led to introduction of the term attention deficit disorder (ADD) with and without hyperactivity. Since then, the criteria have undergone refinements, leading to the current terminology of ADHD with its inattentive, hyperactivity-impulsive, and combined subtypes in DSM-IV (American Psychiatric Association 1994) and its text revision, DSM-IV-TR (American Psychiatric Association 2000; see Table 15–1).