Now in its second edition, this practical handbook assesses global developmental delay and other neurodevelopmental disorders in young children. Explaining diagnostic support, and treatment services available for children and their families, this volume clarifies psychological and medical terminology, and global legislative and societal factors relating to assessment. Fully updated, this new edition incorporates the transition from DSM-5 to DSM-5-TR and has and increased emphasis on cross-cultural and ethnic diversity aspects of assessing and diagnosing neurodevelopmental disorders in young children. Designed as a comprehensive compendium for student and practicing psychologists it offers and introduction to historical perspectives around child development and developmental disorders, and how these have affected our understanding of neurodevelopmental disorder. It explains professional and ethical considerations surrounding the clinical practice of developmental assessments and focuses on the crucial importance of understanding and supporting the parental experience of assessment and diagnosis. Key topics covered include definitions and descriptions of genetic and chromosomal disorders and neurodevelopmental disorders; eligibility criteria for support and assistance; the Griffiths Scales, Bayley Scales, and other notable assessments for young children; autism spectrum disorder; the process of assessment and diagnosis, diagnostic tools, and report writing. Including a chapter of illustrative case studies of children with developmental disorders, this book is essential reading for educational, clinical, and developmental psychologists working with children and their families, as well as postgraduate students training in the field.