Psychiatrists, psychologists, pharmacologists, and pharmaceutical scientists from around the world comprehensively review the pathophysiology, symptomatology, evaluation, and treatment of patients with attention deficit hyperactivity disorder (ADHD). The authors emphasize the evaluation and treatment of patients with ADHD, moving from the day-to-day approach by the clinical psychologist to the more sophisticated anatomical and functional imaging strategies that have emerged in the last decade. Specific impairments, such as reading disabilities, social difficulties, and limited working memory are analyzed in detail, as well as for their respective contributions to global functioning. Additional chapters explain current theories on the pathophysiology of ADHD, focusing on neurotransmitters and the insights gained from animal models. An expanded review of the pharmacotherapy of ADHD includes appropriate methods for selecting of specific drug for individual patients based on drug.