ADHD is characterised by learning and behavioural problems including short attention span, impulsivity, hyperactivity and impairments in perceptual, language and motor skills. Between 4-10% of school-age children are believed to have it with boys outnumbering girls 2-3 to one. An adult form is now recognised. The symptoms of Attention Deficit Disorder are caused by a neurological dysfunction within the brain. The underlying physiological mechanism which causes Attention Deficit Disorder is still not thoroughly understood and remains under intense scientific study. It is presumed that brain chemistry is out of balance and that specific chemicals called neurotransmitters may be lacking in individuals with Attention Deficit Disorder. Leading-edge research from around the world is presented in this book.