Parents and Teachers Should Not Be Misled: Autism, For Now, Includes Those With Intellectual Disability

The author of Autism and Oughtisms has posted a guest comment on the site Teaching the Teachers, Educating an Autistic Child is an Opportunity,  in which, like many other parents and professionals, she includes a commentary which distances autism disorders from intellectual disability:

"There is nothing inherent in autism as a condition, that limits a child’s intelligence or makes them impossible to teach. My own son for example (who has a diagnosis of classic autism) is clearly intelligent and incredibly eager to learn. There are however aspects of autism that will get in the way of learning; it is after all a developmental delay and learning disability."

The author's comment covers a lot of ground.  In the paragraph above I agree with most of what she says. What I disagree with though is the statement that "There is nothing inherent in autism as a condition, that limits a child’s intelligence".  That statement is correct in so far as the definition of autism in the DSM-IV does not require a finding of intellectual disability in order to determine that a child has an autism disorder.  It is true also in the sense that 100% of children with autism do not have an intellectual disability.  But it is misleading in  so far as there is a very clear association between classic autism, or DSM-IV Autistic Disorder and Intellectual Disability.  Parents and teachers should know at the outset that as many as 80%, or the vast majority,  of those with an Autistic Disorder diagnosis will also have an Intellectual Disability.  My sources for that assertion are set out in italics following this comment.   

While it is no longer acceptable to use the term "mentally retarded' to refer to those with intellectual disabilities or to openly mock them, it is still politically correct to exclude the intellectually disabled from consideration for inclusion in many discussions and contexts.  It has happened with the DSM-5 and the New Autism Spectrum Disorder, which will exclude from an autism diagnosis those with an Intellectual Disability, and should more accurately be called Asperger's Spectrum Disorder. It is also true with parents who want the world to know that although their child has an autism spectrum disorder they are not one of those with ... an intellectual disability. 

For the record my son has a diagnosis of Autistic Disorder and he is assessed as having "profound developmental delay".  He has an intellectual disability.   He too, like many autistic children, with or without intellectual disability, is also incredibly eager to learn notwithstanding his autistic disorder and his .... intellectual disability.   


Autism and Intellectual Disability Sources:

1) Canadian Psychological Association Autism Brief to the Standing Senate Committee on Social Affairs, Science and Technology November 9, 2006:


""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.""


2)Department of Health & Human Services - Center for Disease Control Counting Autism NOTE: The CDC surveys indicate the percentages of persons with Intellectual Disability and any Autism Spectrum Disorder including Aspergers.


""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)


2004


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).


2006


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)""


3) CDC Autism Expert Dr. Yeargin-Allsop noted that in the 60's and 70's ... before the DSM changes that added Aspergers (which excludes persons with Intellectual Disabilities) the "vast majority of persons with autism had intellectual disabilities. Not a simple majority ... the vast majority:


CDC Medical Epidemiologist Dr. Marshalynn Yeargin-Allsopp - CMAJ (Canadian Medical Association Journal)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."


4) The ICD-10 Classification of Mental and Behavioural DisordersWorld Health Organization, Geneva, 1992


F84.0 Childhood Autism


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.


Includes:
* atypical childhood psychosis
* mental retardation with autistic features


5) Autism and intellectual disability: a study of prevalence on a sample of the Italian population.


La Malfa G, Lassi S, Bertelli M, Salvini R, Placidi GF.
Psychiatry Unit, Department of Neurological and Psychiatric Sciences, University of Florence, Hospital of Careggi, Florence, Italy. gplamalfa@videosoft.it
Abstract




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.""