This document discusses attention deficit hyperactivity disorder (ADHD), which affects approximately 3-5% of children or around 2 million children in the United States. It notes the difference between ADD, which involves passive inattention, and ADHD, which combines inattention with heightened activity levels and impulsiveness. The document also references the reticular system in the brain of those with ADHD and lists questions to consider in determining if a child has predominantly hyperactive/impulsive type ADHD.