June 2007

Attention-deficit/hyperactivity disorder (ADHD) is the most common neuropsychiatric disorder afflicting children and adolescents in the United States. Epidemiologic studies in the United States indicate that approximately 5% of youths have ADHD.1 ADHD is characterized by the childhood onset of symptoms of inattention, distractibility, impulsivity, and motor hyperactivity that occur in more than one domain of functioning (eg, home, work, school, socially).