The definitive reference in the field—now significantly revised with 75% new material—this volume examines typical and atypical development from birth to the preschool years and identifies what works in helping children and families at risk. Foremost experts explore neurobiological, family, and sociocultural factors in infant mental health, with a major focus on primary caregiving relationships. Risk factors for developmental problems are analyzed, and current information on disorders and disabilities of early childhood is presented. The volume showcases evidence-based approaches to assessment and intervention and describes applications in mental health, primary care, child care, and child welfare settings.