I have written previously that persons who presently have autistic disorder or PDD-NOS and who are also intellectually disabled will be removed from the DSM-5's New Autism Spectrum Disorder. Whereas those with intellectual disability once constituted autism's vast majority as described by CDC autism expert Dr. Marshalyn Yeargin-Allsopp the 1994 addition of Asperger's Disorder reduced their numerical weight on the autism spectrum. With the new DSM-5 wording has intentionally been added to the definition of autism to exclude persons with intellectual disability from autism diagnoses. To be diagnosed with autism a person must meet all 4 criteria, A, B, C and D. Criteria A requires the presence of "persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays." Now, an email exchange between Lisa Jo Rudy of About.com autism spectrum disorders and Dr. Bryan King of the APA's DSM-5's Neurodevelopmental Work Group confirms that the effect of the DSM's New ASD will be to exclude at least some persons with intellectual disability from an autism spectrum disorder diagnosis:
"My Question for Dr. King
There seems to be a desire to remove people with "Persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays" from the ASD category. Does this mean that a child with Mental Retardation (also called Intellectual Delays) no longer qualify for an Autism Spectrum diagnosis? Would that person wind up dually diagnosed with Intellectual Development Disorder and social communication disorder rather than with an ASD diagnosis?
There is no explicit desire , however, by creating more specificity we believe that people may be given diagnoses that better capture their individual conditions. The qualifier above about general developmental delays ensures that the social communication deficits are more specific, and also potentially allows for earlier diagnosis if appropriate.
Just as typically developing infants and toddlers are able to engage in very rich social communication and interaction across contexts, appropriate to their developmental level, so too most individuals with intellectual delays or disabilities are also able to communicate. On the other hand, significant deficits in social communication in toddlers may suggest the presence of autism. What the criterion above is meant to ensure is that clinicians take into account what is typical in terms of social communication abilities at a given age or developmental level, and not assume, for example, that a lack of social perception in a teenager with intellectual disability not automatically suggest the presence of autism. As is currently the case, some individuals with Down Syndrome may also meet criteria for autism; but most will not."
There may or may not be an "explicit desire to move anyone in to or out of specific diagnostic groups" but the wording is being added intentionally to achieve a specific result and it is clear that the intended result is that social communication deficits be more specific that is .... not part of social communication deficits arising in cases of general developmental delay.
The DSM-5's New Autism Spectrum Disorder will add more persons on the high functioning Asperger's end of the spectrum and will reduce the numbers at the lower intellectually disabled end of the spectrum. The vast majority of the original autism described by Dr. Marshalyn Yeargin-Allsoop has been given the boot, kicked off the autism spectrum entirely, or nearly entirely.
There will be no Intellectually Disabled allowed on the DSM-5's New Autism Spectrum.