UNDERdiagnosis of Autism Spectrum Disorders in Individuals with Intellectual Disabilities

A study presented at the IMFAR 2012 conference this spring in Toronto, Underdiagnosis of Autism Spectrum Disorders in Individuals with Intellectual Disabilies, seems to provide evidence contradicting the widely propagated assertion that the DSM-IV era has seen autism incorrectly diagnosed as a substitute  diagnosis in many cases of intellectual disability.  Roeyrs and Thys actually conclude that autism is UNDER diagnosed in a large study of persons with intellectual disability.  

If the study results are confirmed it seems likely  the harmful impact of the express, and intentional,  targeting for exclusion of severe intellectually disabled from the DSM5 autism spectrum disorder will be increased to the detriment of those most severely affected by intellectual disability and autism symptoms.  The missing of co-occurring autism disorder in persons with intellectual disabilities, as the authors indicate, could have serious repercussions for their care and treatment.  

2012 International Meeting for Autism Research

Underdiagnosis of Autism Spectrum Disorders in Individuals with Intellectual Disabilities

Thursday, May 17, 2012

Sheraton Hall (Sheraton Centre Toronto)

3:00 PM

H. Roeyers and M. Thys, Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium

Background: Only a limited number of studies examined the prevalence of autism spectrum disorders (ASD) within the population with intellectual disabilities (ID) and even less studies tried to estimate the proportion of missed diagnoses of ASD in individuals with ID. It is however of great importance that the co-occurrence of ASD is recognized with a view to improving the quality of life of individuals with ASD and their social environment.

Objectives: The first goal of this study was to estimate the prevalence of ASD in a very large sample of individuals with ID. A second and equally important goal was to identify the proportion of overlooked diagnoses in various settings for individuals with ID.

Methods: The sample comprised 2798 individuals with ID and 322 individuals with borderline intellectual functioning from the 5 provinces of Flanders, the Dutch-speaking part of Belgium. The mean age was 25.6 years (SD=16.42), ranging from 1 tot 81 years. 52% of the sample was older that 18. Subjects were screened with the Scale of Pervasive Developmental Disorder in Mentally Retarded persons – Revision, a screening instrument with excellent sensitivity and specificity (Kraijer & de Bildt, 2005).

Results: 633 children and adults were classified as having ASD. This is 21.1% of our sample. When the subgroup with borderline intellectual functioning was excluded, the prevalence rate increased to 22.2%. The male-female ratio was 2:1. Occurrence of ASD was higher in subgroups with more severe forms of ID. 40% of the individuals with an ASD classification had no official diagnosis previously and another 22% was only suspected to have ASD. The proportion of supposedly missed diagnoses was significantly higher in females than in males. ASD was also significantly more often overlooked in adults compared to children. In addition, diagnoses were more likely to be missed in case of an associated genetic disorder such as Fragile X or Down syndrome, a comorbid psychiatric disorder or a severe visual impairment.

Conclusions: This is, to our knowledge, the largest sample of individuals with ID that was ever screened for ASD. Our study confirms that a substantial subgroup screens positive for ASD and that the diagnosis is often missed. Late diagnosis, or the failure to diagnose at all, may have unfavorable and long-standing effects for those affected and their families. For professionals in facilities and schools for individuals with ID it would seem important to bear the possibility of co-occuring ASD in mind. The recognition of ASD could lead to a better understanding of the overall problems of the clients and to more appropriate care and treatment.

After IMFAR Some Green Therapy

My 4 days at IMFAR 2012 in Toronto were an incredible experience. After 4 days spent largely inside a hotel though I was in need of some "therapy". Yesterday I hit the trails for some outdoor Conor time.  Felt great.  

Today more time outdoors enjoying the green city  of Fredericton and its surroundings.  Green therapy works every time.  I should have asked Ilanit Gordon Ph.D. of oxytocin fame to do some fMRI scans to get my baseline measurements at the end of the IMFAR conference and then do some more today after a couple of good outings on the North Riverfront Trail and around Killarney Lake. Oxytocin? Not for me thanks.  Green therapy, absolutely!

Walking With Conor After IMFAR Autism Research Convention

IMFAR was quite an experience.  Very intense. Learned lots, saw lots and met some interesting people. Spent a lot more time indoors then I usually would at this time of year though.  I was glad to get back to Fredericton and get outdoors  walking with Conor today.  And we did lots of walking.  Conor had missed his old Dad while I was gone and his Mom managed the situation by having him check off each day that I was gone on the list above including this morning when he woke up.  He checked Sunday off the list and we hit the trails. Great to be home.

 

                      

 

Ritvo Swedo DSM5 Autism Shootout At The IMFAR Corral

Edward Ritvo-Susan Swedo Shootout at 

the IMFAR Corral, Sheraton, Toronto

Photo by Harold L Doherty, May 18, 2012

Dr. Susan Swedo of the DSM5 autism committee presented a defense of the proposed DSM5 Autism Spectrum Disorder twice yesterday at IMFAR in Toronto.  After the second presentation I jumped up to the mike and asked about the exclusion of Intellectually Disabled under the exclusion wording "not otherwise accounted for by general developmental delays" in the wording for Mandatory Criterion A social communication categories. I was advised that some but not all ID would be excluded.  A couple more questioners approached the mikes on both sides of the room including Dr. Edward Ritvo author of Understanding the Nature of Autism and Asperger's Disorder: Forty Years of Clinical Practice and Pioneering Research.  Dr. Ritvo asked pointed questions about the risk-benefit analysis of introducing the new DSM5 ASD and did not appear happy with the answers he was getting from Dr. Swedo who switched the questioning to the other microphone where Dr. Marshalyn Yeargin-Allsopp was waiting to make a point.  As a layperson, a parent autism advocate with concerns about the DSM5, I am happy that Dr. Ritvo added his prestige and expertise to the debate about the wisdom of the DSM5 autism do-over.  I hope we hear more from Dr. Ritvo on this subject.

DSM5 Autism Day At IMFAR 2012: Swedo Confirms Some Intellectually Disabled Will Be Excluded from DSM5 Autism Spectrum Disorder

Today was DSM5 Autism Do-Over Day at IMFAR 2012.  Dr. Susan Swedo, head of the DSM5 committee that drafted the DSM5 Autism Spectrum Disorder, spoke twice today, once at a stakeholder's luncheon  and afterwards  at an oral presentation in the Grand Ballroom.  Dr. Swedo replied to my questions after the second presentation and indicated that the DSM5 Autism Spectrum Disorder will exclude some, though not all, intellectually disabled from an ASD diagnosis.

I attended both events but did not have an opportunity to question Dr. Swedo during the luncheon as the event was simply running out of time. During the luncheon presentation she was very emotional in discussing the media criticisms of the DSM5  Autism Spectrum Disorder. At one time she accused some in the media of telling lies about the motivation behind the new DSM5.  It was not done, as alleged by some, to cut back the autism epidemic and save costs for insurers.  It was done because the DSM5, according to Dr. Swedo, reflected experience with autism disorders and careful study. It was done to improve specificity in diagnosing autism not to eliminate some.  Having heard her speak with great emotion and conviction I don't question Dr. Swedo's sincerity, her compassion or the motivation behind the redefined DSM5 autism definition.  I do disagree with the specific targeting of intellectually disabled for exclusion from the DSM5.

Dr. Swedo delivered an expanded version of her presentation in a late afternoon session.  Her remarks began, as they did at the luncheon, with a vigorous attack on the media for their DSM5 coverage and misrepresentations about exclusion of high functioning persons with autism and the motives which prompted the new definition. Dr. Swedo said nothing about the exclusion of intellectually disabled until I asked voiced my concerns during the question period about the exclusion of intellectually disabled from the DSM5 definition by operation of the "not accounted for by general developmental delays" exclusionary clause in Mandatory Criterion A of the DSM5's new ASD.  Dr. Swedo indicated that the exclusionary phrase would result in exclusion of some but not all intellectually disabled from a DSM5 Autism Spectrum Disorder.  

Dr. Swedo's comments confirm that the expansion of autism in recent editions will culminate with HFA/Aspergers as the new Autism.   Many of the vast majority of persons with autism and intellectual disability that existed prior to the DSM-IV are now being kicked to the curb; removed from the autism spectrum. 

Intellectual Disability At IMFAR: Underdiagnosis of Autism Spectrum Disorders in Persons with Intellectual Disability

It comes as no surprise but very little is said  about Intellectual Disability at the IMFAR 2012 autism research convention oral presentations.  Prominent autism experts, including Catherine Lord, have noted in the past that intellectually disabled autistics are under represented in autism studies.  This is true even though the vast majority of persons with Autistic Disorder have intellectual disabilities.  The exclusion of the intellectually disabled from autism research reflects the challenges presented by working with low functioning, severely autistic, intellectually disabled subjects.  None of the oral presentations to date focused on the intellectually disabled autistics or discussed issues specific to them. Some studies mentioned that low cognitive subjects were not included but generalized their conclusions to all persons with autism. If you look hard enough though you can find mention of the intellectually disabled hidden in the IMFAR poster sessions.

One such poster involved a Gent University study by Herbert Roeyers and Martine Thys titled Underdiagnosis of Autism Spectrum Disorders in Individuals with Intellectual Disabilities.  The authors point out that only a limited number of studies have examined the prevalence of ASD in ID populations;  of intellectually disabled persons with autism spectrum disorders.  The authors felt it is important to study this co-occurrence relationship between ASD and ID in order to improve quality of life for persons with this co-morbidity relationship. In their study the authors arrived at a prevalence rate of 12.5% of persons with ASD in the ID population studied or approximately 10 times the percentage for persons with ASD in the general population.  Of the numbers identified with ASD only 38% were previously identified as having ASD indicating very serious underdiagnosis of ASD in the Intellectually Disabled population.

While the New York Times expresses great concern over possible future DSM5 exclusion of high functioning autistics, and prompts much reaction from autism experts, neither the NYT, nor most of the experts, even mention current underdiagnosis of autism in people with intellectual disability.

Autism Reality NB at IMFAR 2012 in Toronto, Canada

I am off tomorrow morning, very early tomorrow morning, for the IMFAR 2012 convention in Toronto.  I am very excited to be attending and blogging courtesy of Autism Speaks, Autism Speaks Canada, Dana Marnane and Suzanne Lanthier.  It was a tough day today though. Conor knows Dad won't be home for a few days and he has been a bit agitated.  This afternoon I received a call from the good people at the Leo Hayes High School that Conor was not having a good afternoon. They thought it better that he stay at school until his regular departure time though and I agreed.  When I picked him up I was informed that Conor had in fact calmed down and the rest of the afternoon had gone well.  Conor will miss his old Dad until I return Saturday night.  I might react differently but I will be missing him too.

It is worth it though to attend IMFAR with the annual concentration of autism research and knowledge being hosted in Canada. I am looking forward to blogging about IMFAR from the perspective of a father of a 16 year old son severely affected by his Autistic Disorder.  I underlined Disorder intentionally.  Autism for me is not a culture or a way of life. It is not just a different way of thinking.  It is a serious disorder that restricts my son's life, my son that I love dearly.  I want to attend IMFAR and learn  as much as possible and, hopefully, convey what I have learned, filtered through the perspective I have provided at Facing Autism in New Brunswick for 6 years. It is the perspective of a realistic, caring father who refuses to drink the "autism is a blessing" feel good Kool-Aid of the Neurodiversity advocates who insist on obliterating from public awareness the harsh realities inflicted on so many, including my son, who suffer from autism disorders. 

I hope the IMFAR convention brings news of real progress in autism research.  Although I am a realist I do not give up hope, hope based in solid research.  

I thank Autism Speaks for this opportunity.