ABSTRACT
In 2013, the American Psychiatric Association (APA) published the fifth edition of The Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The DSM-5 included significant changes to the category of pervasive developmental disorders. The most notable change from the previous edition of the manual (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision [DSM-IV-TR]; American Psychiatric Association, 2000), is that Autistic Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder-Not Otherwise Specified (PDDNOS) are now subsumed under one diagnostic category: ASD. This modification was made following the observation that clinicians across different sites were not able to reliably distinguish between the different diagnostic subtypes and often relied on PDD-NOS as a “catch-all” diagnosis for individuals who did not quite meet criteria for Autistic Disorder or Asperger’s Disorder (Lord et al., 2011; Tidmarsh & Volkmar, 2003). Furthermore, it was found that the diagnostic subtypes were not stable, as children matured and developed new competencies in different domains (Lord et al., 2006). Though formerly classified as pervasive developmental disorders, Rett’s Disorder, and Childhood Disintegrative Disorder (CDD) are not included under the new diagnostic umbrella of ASD in the DSM-5. The rationale was that Rett’s Disorder has a known genetic etiology, and CDD is a rare disorder in which children display a pattern of regression that is different than is typically seen in autism (Rogers, 2004).
