This comprehensive, 51-chapter handbook presents recent advances in the expression, etiology, assessment, and treatment of child and adolescent psychiatric disorders and related problems from a developmental psychopathology perspective. Following a broad conceptual overview of this area of clinical research and practice, assessment and treatment practices are examined for specific DSM-5 disorders and other nondiagnostic but nonetheless significant problems in childhood and adolescence, including the maltreatment of youth, children of divorce, children with incarcerated parents, nonsuicidal self-injury among youth, youth with suicidal thoughts and behavior, children who bully or are bullied, youth with medical conditions, and youth with neurobehavioral disorders. The practice of clinical child and adolescent psychology is then explored in diverse settings.