Attention-Deficit Hyperactivity Disorder or Hyperactivity (ADHD), disorder beginning in childhood, characterized by a persistent inability to sit still, focus attention on specific tasks, and control impulses. Children with ADHD show these behaviors more frequently and severely than other children of the same age. A person with ADHD may have difficulty with school, work, friendships, or family life. ADHD has also been referred to as attention-deficit disorder, hyperkinesias, minimal brain dysfunction, and minimal brain damage.
Attention-deficit hyperactivity disorder is one of the most common mental disorders of childhood, affecting 3 to 5 percent of school-age children. The disorder occurs at least four times more often in boys than in girls. Although the symptoms sometimes disappear with age, ADHD can persist into adolescence and adulthood. Some estimates show that up to 2 percent of adults have ADHD.
Diagnosing ADHD is difficult because most children are inattentive, hyperactive, and impulsive at least some of the time. In diagnosing ADHD, experts use guidelines listed in the Diagnostic and Statistical Manual of Mental Disorders. These guidelines require that a child show behaviors typical of ADHD before the age of seven. The behaviors must last for at least six months, and must occur more frequently than in other children of the same age. The behaviors also must occur in at least two settings, such as classroom and home, rather than just at a single setting.
Controversy exists over the diagnosis of ADHD. Physicians in the United States diagnose the disorder more often than doctors elsewhere in the world. Critics regard this discrepancy as evidence that physicians and psychologists too often apply psychiatric labels to children who are naturally more active or simply nuisances to teachers and parents.
Children and adults with ADHD consistently show various degrees of inattention, hyperactivity, and impulsiveness.