This article introduces the revised and updated "DC:0-5™: Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood." The authors describe the past and current efforts to create a developmentally based classification system for very young children. DC:0-3, published in 1994 by ZERO TO THREE,…

From the time of conception to the first day of kindergarten, development proceeds at a pace exceeding that of any subsequent stage of life. Relationships and experiences with parents, caregivers, and preschool teachers during these early years "form the foundation and scaffold on which cognitive, linguistic, emotional, social, and moral…

This policy brief begins with a broad overview of what the science of early childhood development tells us about the first three years of life. It then outlines the actions that need to be taken during the reauthorization of the Individuals with Disabilities Education Act (IDEA) to increase the likelihood that policy decisions are guided by state…