Telling the difference between autism and Asperger’s
Nicole Rinehart receives funding from NHMRC
The Conversation provides independent analysis and commentary from academics and researchers.
We are funded by CSIRO, Melbourne, Monash, RMIT, UTS, UWA, Canberra, CDU, Deakin, Flinders, Griffith, La Trobe, Murdoch, QUT, Swinburne, UniSA, UTAS, UWS and VU.
Founding Partner of The Conversation.
Articles by This Author20 March 2012 Five myths about autism 17 August 2011 One-in-five risk of sibling autismWhile they share some traits, Asperger’s and autism are separate disorders.
Parents often breathe a sigh of relief when their child takes his first step, speaks her first word, and can spontaneously read his mother’s facial expression.
For children with autism, they might take the first step like all other children, but the first word and emotional communication might be a long way off. In some cases, it may never come.
The journey is different for a child with Asperger’s disorder. The first word may be early, followed by an explosion of language. Soon parents start wondering whether he might be gifted.
But these thoughts quickly become sidelined by concern as the child enters school and seems to struggle with friendships, play, and seems rigid and obsessive, despite a fantastic vocabulary.
Parents may become concerned because their child just never seems to be able to hit the mark socially, emotionally, and academically. And there is something unusual about the intensity of the child’s interests which seem to take over their life.
Our current psychiatric manual, the Diagnostic and Statistical Manual (DSM) Fourth Edition, catagorises autism and Asperger’s disorder as separate disorders. This is based on the very different challenges these young people face with language, and cognitive development.
But soon this will change, and the two disorders will be grouped under one umbrella term.
Understanding the difference
There is no clear biomarker or genetic test which can define or separate autism and Asperger’s disorder.
With some families' diagnostic journey beginning in late primary school or even in secondary school, differentiating between autism and Asperger’s disorder can be difficult.
In the absence of an extensive developmental history of language and social development, two normally intelligent young people, one with autism, the other with Asperger’s disorder, both presenting with social difficulties, and a history of repetitive, stereotyped behaviour, may appear to have the same struggles.
The common challenges and interests may even be the bedrock for a wonderful friendship between a child with autism and Asperger’s disorder.
The dilemma with this differentiation has fuelled a debate in clinical and academic circles spanning two decades: are autism and Asperger’s disorder the same disorder and should be “lumped” together diagnostically, or should we continue to “split” them.
To overcome the clinical confusion between a diagnosis of autism and Asperger’s disorder, the working party for the Fifth Edition of the Diagnostic and Statistical Manual has recommended that Asperger’s disorder be incorporated with autism under the category of Autism Spectrum Disorders (ASDs).
Origins of autism and Asperger’s
Autism was first described by Leo Kanner in 1943 when he studied 11 children who seemed to relate better to objects than people.
Kanner said if these children eventually developed language skills, it was likely to be characterised by echolalia (repetition of words or syllables), pronoun reversal (referring to themselves as others have referred to them), and concreteness.
One year after Kanner defined autism, Hans Asperger published a description of children with the condition “autistic psychopathology”.
Asperger described a child who was precocious in learning to talk and often talked in a pedantic way about a topic of particular, circumscribed interest.
Asperger also observed that these children produced stilted and repetitive speech, which appeared to lack intonation. He noted that they were interested in social relationships, but lacked the ability to understand the rules of social behaviour.
Asperger noted that his group of patients moved in a “clumsy” way.
Despite the many similarities between Kanner’s and Asperger’s patient groups, Asperger disagreed that his disorder was a variant of Kanner’s autism.
We have only known about Asperger’s disorder since 1981 when Hans Asperger’s work was translated into English (refer to Rinehart et al, 2002 for complete historic references).
Asperger’s disorder did not appear as a separate disorder in standard diagnostic manuals until version four of the DSM series, only 16 years ago.
Looking back I can recall several young people I knew in my community who had significant social and communication difficulties, but were very bright and verbally able.
These young people were not diagnosed with any mental health disorders but were marginalized and seen as the “quirky kids” or eccentric, and had an underlying sadness.
There is no doubt the inclusion of Asperger’s disorder in DSM-IV-TR has positively impacted on the lives of these young people who are now better understood for their individuality, and have the support of wonderful organisations and support groups.
Categorising Asperger’s disorder as a milder type of autism is problematic because it implies that life is less challenging for a child with Asperger’s disorder compared to a child with autism.
But in some cases, young people with Asperger’s can suffer from more severe anxiety and depression than their peers who have been diagnosed with autism – and there is nothing mild about clinical anxiety and depression.
The Asperger’s label has also served as an important guide to help parents successfully link their children to fulfilling and rewarding social settings, activates, and later, careers.
The label change comes as some new discoveries are being made to better understand the disorders, including brain differences and subsequent diagnostic and treatment tools.
Melbourne researchers are using Transcranial Magnetic Stimulation to show that cortical inhibition, a common brain process that allows the suppression of brain cell activity, is impaired among young people with high-functioning autism, but not among young people with Asperger’s disorder.
The movement pattern or gait studies conducted at Monash University have shown that children with autism have a particular style of walk. Given that children walk before they develop social skills, understanding early walking patterns might expedite autism diagnosis.
The different life journey a child with Asperger’s disorder may take compared to a child with autism, together with other brain and psychological differences, may inform the future development of assessment tools, biomedical and other treatments for each disorder.
And who knows, in the future there may be a stronger scientific basis to argue against the lumping of the autism and Asperger’s disorder diagnostic category. Only time will tell.
Rinehart, N. J., Bradshaw, J.L., Brereton, A. V., Tonge, B.J. (2002). A clinical and neurobehavioural comparison of high-functioning autism and Asperger’s disorder. Australian and New Zealand Journal of Psychiatry, 36, 762-770.