In a Nutshell - a collection of current knowledge on neurobehavioral disorders, this book explores phenotypes and the genetic background of disorders, and applies this foundational knowledge to current treatment and therapy practices. This book, derived from the 2008 Spectrum Conference, focuses on neurobehavioral disorders and the influence of genetics in particular. It provides foundational information for clinicians and examines behavioral and psychological phenotypes in specific neurobehavioral disorders including Down Syndrome, Fragile X, Fetal Alcohol Syndrome, Prader-Willi Syndrome, Smith Magenis Syndrome, and Williams Syndrome, among others. The final section of the book applies genetic insights and the disorder-specific background as a framework for evaluating challenges and promise in intervention.