“High-functioning autism” is a misleading term that should be retired from clinical and academic language, West Australian researchers say, warning that the concept could be preventing people getting the support they need.
While not a medical diagnosis, the phrase was coined by researchers to denote autistic people without intellectual disability, defined as having an IQ over 70. It was used synonymously with Asperger’s, which is no longer an official diagnosis in the Diagnostic and Statistical Manual of Mental Disorders.
But IQ is not, in fact, a good predictor of functioning, according to a study by the Telethon Kids Institute at the University of Western Australia, published in the journal Autism. This matters, because cognitive tests are often used to determine eligibility for services.
The research compared the cognitive and functioning abilities of 2225 children and adolescents with autism, using the Western Australian Register for Autism Spectrum Disorders. About half the subjects had intellectual disability.
Cognitive ability was measured by IQ test, and functioning was measured using the Vineland Adaptive Behaviour Scale, which rates everyday skills such as communication, social interaction and self-care relative to age group.
Lead author Dr Gail Alvares told The Medical Republic that for those without intellectual disability, functioning scores were far lower than what their IQ scores would have predicted.
“What this tells us is that the label of high-functioning is very inaccurate: it doesn’t tell you anything about someone’s functional abilities,” Dr Alvares said.
“The term really conveys the expectation that a person should be able to cope at the same level as their peers in situations that require social interaction or communication skills – when actually we’re just talking about an IQ difference.
“When we use those IQ scores or a cognitive estimate clinically, we’re using them to estimate how much support a person might need in a school or work environment.”
As for what language to use, “autism spectrum disorder without intellectual impairment” is the correct diagnostic term, Dr Alvares said. “High-functioning” would be appropriate if based directly on a functional assessment.
“But many people in the autistic community have said the term is not helpful at all, and they would like to see us stop using it,” she said. “Potentially we should be asking the autistic community what language we should be using.
“Some have suggested using support level as a term, so you could talk about someone with high support needs or low support needs.”
A child might pass a cognitive test as well as their peers, she said, but that doesn’t mean they can keep up at a mainstream school – to write and take notes at the same speed, deal with the structured and unstructured aspects of school life, or take public transport.
“They may have additional sensory challenges – they might hear things that we filter out, or smell things that we can’t, or the fluorescent lighting might have an impact.
“When we’re assuming that just because they’re performing at a certain cognitive level that they can cope, it’s overestimating what that individual might be able to accomplish.”
The study also confirms the apparent decline in functioning scores with age, reflecting that as the tasks expected of us become more complex, people with autism fall further and further behind their age group.
Australia’s National Disability Insurance Scheme recognises the need for functional rather than cognitive criteria, assigning funding according to current functional capacity and the amount of support required to participate in everyday activities expected of a person that age.
But many US states, the paper says, determine eligibility for services explicitly on the basis of an IQ below 70, rather than a functional assessment.
Even successful people who appeared to “function” very well might face difficulties that weren’t apparent, Dr Alvares said.
“[Australian comedian] Hannah Gadsby is a great example of someone who is able to communicate very well, but she may still experience significant challenges. Many autistic individuals I know who have PhDs or are professors can still have challenges, and we need to understand those difficulties to be able to support them – in the same way we provide wheelchair ramps, there are lots of simple environmental accommodations that can greatly improve quality of life for many autistic people.
“So we need input from our autistic community about how we can support them and allow their full potential to shine.”
Autism, online 19 June