Rich with clinical insights, this volume reviews the state of the science of identifying and treating autism spectrum disorders (ASD) in very young children. Leading authorities examine critical research issues and present innovative approaches to assessing social, cognitive, adaptive, communication, and sensory-motor impairments in the first two years of life. Providing a comprehensive discussion of developmental, behavioral, and medical intervention models, the book also addresses ways to support families in coping with an early ASD diagnosis and becoming effective advocates for their children. A special chapter discusses popular but controversial treatments, including how to help families make informed decisions about their use.