The definition of autism spectrum disorder is being revised and two of its current components, Asperger syndrome and PDD-NOS (pervasive developmental disorder-not otherwise specified), are among the diagnoses that would be eliminated in a new manual due out next year. The DSM — the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association (APA) — is the official guide for many healthcare professions. The APA is currently undertaking field trials and receiving comments for its next edition, the DSM-5, tentatively due out in May 2013.
The DSM incorporates the latest scientific research and clinical data into its classification system. It’s a “work in progress,” said James C. Harris, MD, director, Developmental Neuropsychiatry Clinic at The Johns Hopkins Children’s Center in Baltimore, MD, founder of the autism clinic at Johns Hopkins, and author of a definitive text on the subject.
Changes in Autism Labels
Several proposed revisions will affect the way current autism labels are handled. In short, there will now be one category called autism spectrum disorder (ASD) and a brand new diagnostic category called social communication disorder.
Autism spectrum disorders will encompass all variations within the spectrum, from severe to mild manifestations. Separate components, such as Asperger syndrome, will be dropped for several reasons, says Dr. Harris, who serves on the Neurodevelopmental Disorders Workgroup to review these diagnosis categories.
The new social communication disorder category is outside the autism spectrum and will likely become a common diagnosis, Dr. Harris says.
Reasons for the Changes
Here's how the Workgroup explains its rationale in changing autism definitions: “A single spectrum better reflects the pathology and symptoms. Separation of ASD from typical development is reliable and valid, while separation of disorders within the spectrum is variable and inconsistent.” [italics added] Dr. Harris points out, for instance, that published clinical reports have difficulty distinguishing between high functioning autism (HFA) and Asperger syndrome.
The new social communication disorder is distinct and separate from ASD. The thinking is that individuals who have trouble only with certain pragmatic aspects of communication, but who show no other characteristics of autism, will now have a separate diagnosis category. It is intended to capture youngsters who need help, without “medicalizing” those who are merely quirky or geeky.
Asperger syndrome joins lots of other “eponymous” syndromes being dropped throughout the upcoming DSM-5. In these cases, the broader diagnostic label is favored over using the person for whom a set of symptoms was named.
PDD-NOS as a separate diagnosis is also scheduled for elimination. “It’s not a useful term,” said Dr. Harris, who notes that there are more than 20 different genetic syndromes associated with that current diagnosis.
"Lumpers" and "Splitters"
Dr. Harris acknowledges that these proposals have prompted commentary by professionals — those who want to lump the categories together and those who want to split them off — the "lumpers" and the "splitters." Science is a dynamic process.
Criteria used in the new ASD description are also being modified. Dr. Harris says that although communication, social interaction and repetitive behaviors and limited interests are still included, they are reorganized and more specific in the revised formulation. This may mean that it will be harder to meet these criteria, and that fewer individuals may qualify for a specific ASD diagnosis.
DSM reflects the best scientific consensus at a given point in time. That means it is subject to change, reflecting more current research and clinical experience. Revisions will always be on the horizon, as more is learned about disorders in the autism spectrum and beyond.
Ann L. Rappoport, PhD, is a contributing writer to MetroKids.
