The Need for Revision

DC:0-3 was revised for several reasons:

• To account for the expected evolution of the classification system since its initial publication;
  
  
• To address limitations in the system that users have identified, such as lack of criteria in some classification categories and, in others, criteria that needed clarification;
  
  
• To examine the system for its value in clinical formulation of individual cases and treatment planning; and
  
  
• Perhaps most importantly, to incorporate the new knowledge and clinical experiences from the past decade.

The DC:0-3R Multiaxial System
DC:0-3R continues the multiaxial classification system that has been so useful in clinical formulation. Use of the multiaxial system for clinical formulation focuses the clinician's attention on the factors that may be contributing to the difficulties of the infant or young child, adaptive strengths, and additional areas of functioning in which intervention may be needed.

The labels for DC:0-3R's axes are essentially the same as those in DC:0-3, incorporating some changes in wording recommended by users:

Axis I: Clinical Disorders
Axis II: Relationship Classification
Axis III: Medical and Developmental Disorders and Conditions
Axis IV: Psychosocial Stressors
Axis V: Emotional and Social Functioning

Each axis is described in detail in the book. Additionally, Appendix A, "Prioritizing Diagnostic Classification and Planning Intervention," provides guidelines for thinking about diagnosis and selecting classifications.

Significant Changes
Most of the differences that distinguish DC:0-3R from DC:0-3 specify and clarify criteria for the classification categories already designated in Axis I of DC:0-3. Although the Revision Task Force did not intend to change or add major classification categories, the group was authorized to make changes when there was strong evidence in favor of doing so. These changes include the following:

• "Gender Identity Disorder" was removed because we found no evidence for its meaningful classification in the early years.
  
  
• We changed the name of "Reactive Attachment Deprivation/Maltreatment Disorder of Infancy," removing "reactive attachment" from its earlier designation; criteria are added where none had existed before. The description of the renamed Deprivation/Maltreatment Disorder includes criteria where none had existed before.
  
  
• "Traumatic Stress Disorder" is renamed "Posttraumatic Stress Disorder," to emphasize congruence with the syndrome that is commonly understood and designated in DSM-IV-TR; criteria are added where none had existed before.
  
  
• "Regulatory Disorders" is renamed "Regulation Disorders of Sensory Processing " in order to draw attention to the difficulties in sensory processing that characterize these disorders.
  
  
• Descriptions of Sleep Behavior Disorders and Eating Behavior Disorders incorporate subtypes and criteria from Research Diagnostic Criteria-Preschool Age (RDCPA) that seem appropriate for toddlers. DC:0-3R notes that Sleep Behavior Disorders can be appropriately classified after 12 months of age, when sleep patterns typically emerge.

Additionally, after reviewing new evidence for DSM-IV-TR-related classifications, the DC:0-3R Revision Task Force adopted the following classifications from the American Academy of Child and Adolescent Psychiatry's RDCPA:

• Subclassifications of anxiety disorder after the age of 2 years;
  
  
• The use of Pervasive Developmental Disorders, including autism, PDD-NOS, after 2 years of age.
  
  
• DC:0-3R retains Multisystem Developmental Disorder as a possible classification for children under the age of 2 years.
  
  
• Subclassifications for Sleep Behavior Disorders; and
  
  
• Subclassifications for Feeding Behavior Disorders.