Saturday, April 02, 2011

Unfulfilled Promise: Intellectual Disability Ignored on World Autism Awareness Day

Today is World Autism Awareness Day (WAAD). The establishment of WAAD held out great promise of elevating the world's understanding of the realities of autism spectrum disorders and the challenges they present to those diagnosed with one of the Pervasive Development Disorders slotted for merger into the New Autism Spectrum Disorder in the DSM5.  The promise, however, remains largely unfulfilled.  The world has learned to associate autism with the color blue but beyond that the very serious realities of those with autism and intellectual disability, those who are very low functioning, those who are self injurious, those who wonder away, some never to return alive,  are rarely spoken of in the rah rah fund raising promotions which mark the onset of World Autism Awareness Day.  Intellectual Disability, in particular, remains the  elephant in the autism living room, a very large presence of which no one speaks.

Autism Speaks was one of the prime movers in establishing World Autism Awareness Day.  The official Autism Speaks WAAD site describes what autism is in very general terms but makes no mention of the very close association between Intellectual Disability and Autistic Disorder or classic autism with as many as 80 % of all persons with Autistic Disorder also having Intellectual Disability:

What is the intellectual disability component of autism that no one mentions this World Autism Awareness Day?

From 30% to 60% of children with an autism spectrum disorder (ASD) have an IQ measure that falls in the intellectual disability (ID) range.

(Catherine Rice et al., Risk for cognitive deficit in a population-based sample of U.S. children with autism spectrum disorders: Variation by perinatal health factors, Disability and Health Journal, Volume 3, Issue 3, Pages 202-212 (July 2010)

Autism and intellectual disability: a study of prevalence on a sample of the Italian population.
Psychiatry Unit, Department of Neurological and Psychiatric Sciences, University of Florence, Hospital of Careggi, Florence, Italy.


BACKGROUND: In 1994, the American Association on Mental Retardation with the DSM-IV has come to a final definition of pervasive developmental disorders (PDD), in agreement with the ICD-10. Prevalence of PDD in the general population is 0.1-0.15% according to the DSM-IV. PDD are more frequent in people with severe intellectual disability (ID). There is a strict relationship between ID and autism: 40% of people with ID also present a PDD, on the other hand, nearly 70% of people with PDD also have ID. We believe that in Italy PDD are underestimated because there is no agreement about the classification system and diagnostic instruments.
METHOD: Our aim is to assess the prevalence of PDD in the Italian population with ID. The Scale of Pervasive Developmental Disorder in Mentally Retarded Persons (PDD-MRS) seems to be a very good instrument for classifying and diagnosing PDD.

RESULTS: The application of the PDD-MRS and a clinical review of every individual case on a sample of 166 Italian people with ID raised the prevalence of PDD in this population from 7.8% to 39.2%.

CONCLUSIONS: The study confirms the relationship between ID and autism and suggests a new approach in the study of ID in order to elaborate a new integrated model for people with ID.

Definition: Autism is a pervasive developmental disorder, first identified by Kanner in 1943. Decades later, Autism came to be viewed as the more severe of the Autism Spectrum Disorders (ASD) which also include Asperger’s Disorder. ASD is a heterogeneous disorder that includes a range of developmental impairments in the areas of social skills, verbal and non-verbal communication as well as restricted or repetitive interests or behaviours.

Symptoms and Impairments:

• Cognitive impairment is present in about 80% of persons diagnosed with Autism and
general intellectual functioning is most often below average. Persons diagnosed with
Asperger’s Disorder have average to above average intellectual functioning.
CDC Medical Epidemiologist Dr. Marshalynn Yeargin-Allsopp - CMAJ Interview 

"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."

[Note: Dr. Yeargin-Allsopp's figure of "about 40% with an ID is for the entire Autism Spectrum and is lowered because of the inclusion of Aspergers which, as a diagnosis, excludes ID]

Department of Health & Human Services - Center for Disease Control Counting Autism 

CDC’s most recent data show that between one in 80 and one in 240 children with an average of one in 110 have an ASD. This is a prevalence of about one percent of children. These results reflect data collected by CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network in multiple communities throughout the U.S. in 2006. 

Estimates are based on health and education records from participating communities, which includes eight percent of the U.S. population of eight year olds. All children in the studies were eight years old because previous research has shown that most children with an ASD have been identified by this age for services.
Cognitive Functioning (from the pdf version)


From 37.9% (Arizona) to 63% (Alabama) (overall average: 43.8 %) of the children identified with an ASD also had an intellectual disability (an IQ ≤70, at the sites that had test results on intellectual ability for at least 75% of the children identified).


From 29.3% (Colorado) to 51.2% (South Carolina) (overall average: 41.0 %) of the children identified with an ASD also had an intellectual disability (an IQ ≤70, at the sites that had test reults on intellectual ability for at least 75% of the children identified)
A pervasive developmental disorder defined by the presence of abnormal and/or impaired development that is manifest before the age of 3 years, and by the characteristic type of abnormal functioning in all three areas of social interaction, communication, and restricted, repetitive behaviour. The disorder occurs in boys three to four times more often than in girls. 


All levels of IQ can occur in association with autism, but there is significant mental retardation in some three-quarters of cases. 

F84.1 Atypical Autism

A pervasive developmental disorder that differs from autism in terms either of age of onset or of failure to fulfil all three sets of diagnostic criteria. Thus, abnormal and/or impaired development becomes manifest for the first time only after age 3 years; and/or there are insufficient demonstrable abnormalities in one or two of the three areas of psychopathology required for the diagnosis of autism (namely, reciprocal social interactions, communication, and restrictive, stereotyped, repetitive behaviour) in spite of characteristic abnormalities in the other area(s). Atypical autism arises most often in profoundly retarded individuals whose very low level of functioning provides little scope for exhibition of the specific deviant behaviours required for the diagnosis of autism; it also occurs in individuals with a severe specific developmental disorder of receptive language. Atypical autism thus constitutes a meaningfully separate condition from autism.
* atypical childhood psychosis
* mental retardation with autistic features


blogzilly said...

This post gave me a HUGE amount to think about, but it really opened some doors to some things that have been on the tip of my mind but I haven't been able to crystallize.

Very good post.

Anonymous said...

Thanks for the great information , i learned a lot and will be sharing your link too. peace