DC:0-5™: Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (ZERO TO THREE, 2016) emphasizes the centrality of relationships for young children's development and psychopathology. The authors share the story of a young child and his mother to illustrate the use of DC:0-5, with an emphasis on how ratings of the primary caregiving relationships and the caregiving environment are used in the assessment process to create a treatment plan for the child and family.