DEFINING RELATIONAL PATHOLOGY IN EARLY CHILDHOOD: THE DIAGNOSTIC CLASSIFICATION OF MENTAL HEALTH AND DEVELOPMENTAL DISORDERS OF INFANCY AND EARLY CHILDHOOD DC:0-5 APPROACH.

Infant mental health is explicitly relational in its focus, and therefore a diagnostic classification system for early childhood disorders should include attention not only to within-the-child psychopathology but also between child and caregiver psychopathology. In this article, we begin by providing a review of previous efforts to introduce this approach that date back more than 30 years. Next, we introduce changes proposed in the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood DC:0-5 (ZERO TO THREE, in press). In a major change from previous attempts, the DC:0-5 includes an Axis I "Relationship Specific Disorder of Early Childhood." This disorder intends to capture disordered behavior that is limited to one caregiver relationship rather than cross contextually. An axial characterization is continued from the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood DC:0-3R (ZERO TO THREE, 2005), but two major changes are introduced. First, the DC:0-5 proposes to simplify ratings of relationship adaptation/maladaptation, and to expand what is rated so that in addition to characterizing the child's relationship with his or her primary caregiver, there also is a characterization of the network of family relationships in which the child develops. This includes coparenting relationships and the entire network of close relationships that impinge on the young child's development and adaptation.