A recent study conducted by the U.S. Centers for Disease Control estimated that approximately 7.8 percent of U.S. children ages 4-17 are currently diagnosed with Attention Deficit Disorder (ADD) or Attention Deficit/Hyperactivity Disorder (ADHD). For decades, most educators, physicians, psychologists, and parents have thought of ADD/ADHD as essentially a cluster of behavior problems, a label for children who can't sit still, won't stop talking, and often are disruptive in class. Increasingly, specialists are recognizing that it is a complex syndrome of impairments in development of the brain's cognitive management system, or "executive functions." The disorder affects one's ability to manage such activities as organizing and getting started on work tasks, attending to details, staying alert, remaining focused, and managing emotions appropriately. Children can manifest symptoms of ADD/ADHD as early as preschool or as late as the college years. Medication treatment can help some students by making them more available to learn. Other students will require both medication and special education services to alleviate their learning disability problems. (Contains 1 endnote.)