The fully revised and updated Oxford Handbook of Infant, Toddler, and Preschool Mental Health Assessment remains the first clinically-informative, research-based reference for those seeking to understand and assess mental health in infants and young children. It details the latest empirical research on measures and methods of infant and young child assessment and provides clinically applicable information for those seeking to stay apprised of the latest empirical research on measures and procedures in early assessment. Through authoritative examination by leading developmental and clinical scholars, this handbook takes a closer look at current developmentally based conceptualizations of mental health function and dysfunction in infants and young children as well as current and new diagnostic criteria in specific disorders such as sensory modulation dysfunction, autism spectrum disorders, affective disorders, and post-traumatic stress disorder. The chapters are presented in four sections corresponding to four broad themes: contextual factors in early assessment; temperament and regulation in assessment of young children; early problems and disorders; and translation and varied applied settings for assessment. Each chapter presents state of the science information on valid, developmentally based clinical assessment and makes recommendations based on developmental theory, empirical findings, and clinical experience. Chapters have been added to cover family assessment, early care and educational environments, new approaches to distinguish temperament from psychopathology, assess language, and implement second stage screening and referral. The volume recognizes and highlights the important role of developmental, social, and cultural contexts in approaching the challenge of assessing early problems and disorders. This new, updated volume will be an ideal resource for teachers, researchers, and a wide variety of clinicians and trainees including child psychologists and psychiatrists, early interventionists, and early special educators.