Autistic Disorder and Intellectual Disability: 70% Is Not a Coincidence, It Is a Vast Majority

                                  

The DSM-IV and popular media interpretation of the autism disorders (pervasive developmental disorders), have encouraged the world to see autism as shy or introverted personality and a different, sometimes superior, way of thinking and has obscured the very obvious and close connection between autistic disorder, the most severe form of autism, and intellectual disabilities.

Autism is described in a CHARGE Study article as follows (emphasis added, HLD):

"Autism is a serious neurodevelopmental disorder characterized by impairments in social interaction, abnormalities in verbal and nonverbal communication, and restricted, stereotyped interests and behaviors (American Psychiatric Association 1994). Although a large proportion of individuals with autism manifest abnormal development from birth, a subset of at least 20–30% experience a regression with onset between 18 and 24 months of age after a period of apparently normal development (Lainhart et al. 2002). Autistic disorder is the most severe form of autism spectrum disorders (ASDs), which include Asperger’s syndrome and pervasive developmental disorders (PDDs) not otherwise specified. Approximately 70% of individuals with autistic disorder have some degree of mental retardation, and about half are nonverbal or have very impaired speech.

The CHARGE Study: An Epidemiologic Investigation of Genetic and Environmental Factors Contributing to Autism, Irva Hertz-Picciotto et al.

CDC autism expert Dr. Marshalyn Yeargin-Allsopp has described those with intellectual disability as the "vast majority" of the original,  pre DSM-IV autism:

"But the autism umbrella has since widened to include milder forms, says Dr. Marshalyn Yeargin-Allsopp, a medical epidemiologist at the CDC. For example, it now includes Asperger syndrome, where the sufferer is socially impaired, but experiences typical language development.

Another difference between past and present autism diagnosis involves the presence of intellectual disabilities, adds Yeargin-Allsopp. During the 1960s and 1970s, the vast majority of those diagnosed with autism had an intellectual disability but today, only about 40% have one."

CDC Autism Expert Dr. Marshalyn Yeargin-Allsopp 

The attempt to hide the very strong and clear relationship between autistic disorder and intellectual disability is more than just wrong it is the last politically correct form of discrimination ... discrimination against those with intellectual disabilities.  It is also a huge step backwards in understanding the truth about autism, that autism is a form of intellectual disability, most evident in those with autistic disorder.  Studies of high functioning persons with autism and Asperger's are routinely reported as representing all persons with autism disorders even those with intellectual disability who are intentionally excluded from the studies.