Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Attention deficit-hyperactivity disorder (ADHD) is a psychiatric and a neurobehavioral disorder which is characterized by either significant difficulties of inattention or hyperactivity and impulsiveness or both. The Diagnostic and Statistical Manual of Mental Disorders said that symptoms of ADHD emerge before seven years of age. It causes children to be restless, to act impulsively, and to lack concentration, affecting their ability to learn properly. ADHD is the most commonly studied and diagnosed psychiatric disorder in children with about 3% to 5% of children affected globally. 30% to 50% of children diagnosed with ADHD continue to have symptoms into adulthood...