The volume is an international book of collected papers by 26 eminent specialists from eight different countries and many parts of the world (America, Brazil, India, Mexique, Poland, Portugal, Russia, and Turkey), dealing with the problem of Attention Deficit Hyperactivity Disorder (ADHD). This disorder interferes to a great extent with functioning and development of children at different age. The volume provides a contemporary and future - oriented view of the issues and concepts in the pattern, mechanisms and remediation of ADHD. They include problems of social functioning and learning disability of children with ADHD, psychological, physiological, genetic and neurological mechanisms, cerebral substrate and aetiology of this form of dysontogenesis, forensic implications for behavioural disturbances associated with childhood ADHD, practical suggestions for clinicians and psychologists, new methods of its assessment and efficient methods and approaches to remediation of children with ADHD. This disorder became an important international problem, independently of cultural and economic conditions of life, styles of education, learning systems with a prevalence of about 5% -7% in most cultures. Therefore better understanding of children suffering Attention Deficit Hyperactivity Disorder could help these children, their parents and educators to develop efficient treatment plans and integrated approaches that are uniquely tailored to each individual child.