Attention-Deficit/Hyperactivity Disorder (ADHD) is the name of a group of attention-related symptoms that are often found together, especially in children and young adults. ADHD often starts to become apparent in the middle elementary school years, and symptoms can last into adulthood. Symptoms include inattention, hyperactivity, and impulsivity. It is estimated that ADHD affects approximately 2 million children in the United States. This comprehensive book explores the nature of ADHD, its history, how it is diagnosed and treated, and its possible causes.