Dylan Dyke, a 12-year-old boy with autism, spends time with his ducks, Nibbles, left, and Bill, outside his home in Michigan on Aug. 2, 2018. (Cory Morse/The Grand Rapids Press via AP)

Dylan Dyke, a 12-year-old boy with autism, spends time with his ducks, Nibbles, left, and Bill, outside his home in Michigan on Aug. 2, 2018. (Cory Morse/The Grand Rapids Press via AP)

New study suggests autism overdiagnosed: Canadian expert

Laurent Mottron: ‘Autistic people we test now are less and less different than typical people’

Autism has become so overdiagnosed that within five to 10 years there could be almost no difference between groups of people who have been diagnosed with the condition and those who haven’t, a Montreal researcher warns following the publication of a new study.

A new meta-analysis published Wednesday in JAMA Psychiatry that analyzed 11 previous major studies carried out since 1966 found that individuals diagnosed with autism have become progressively less different from the general population.

Laurent Mottron, a research psychiatrist at the mental health unit of the Riviere-des-Prairies Hospital and one of the study’s authors, said the gap could soon narrow to nothing.

“Autistic people we test now are less and less different than typical people — really less and less, to the point where if the trend continues, we won’t be able to find the least difference within five or 10 years,” he said in an interview.

Mottron says the problem is that the criteria have lowered to the point where a diagnosis could become nearly meaningless.

Mottron and four other researchers conducted a meta-analysis of previous studies that compared people who have been diagnosed with autism with those who haven’t. The analysis, which included data from 27,723 individuals, includes practically “the whole of planetary research on the autistic brain,” he said.

The analysis found that the differences between the groups have decreased over time in five of the seven main constructs that define autism, including emotion recognition, theory of mind, planning and brain size.

READ MORE: B.C. parents hope service dog helps stop autistic child’s self-harming

In contrast, the group found no such tendency when it comes to the prevalence of schizophrenia, which has remained stable for the past two decades.

Globally, the number of people diagnosed with autism has risen dramatically in recent years, going in the United States from less than 0.5 per cent of the population in 1966 to more than two per cent. In Quebec, the number is approaching two per cent.

The study’s authors say their findings may be due to several factors, including a true increase in the condition, greater public awareness, the fact that a diagnosis leads to greater support, a lowered threshold for diagnosis, the use of “checklist diagnoses” and a greater tendency to diagnose individuals with a normal IQ.

They note that understanding of autism has also evolved ”from a narrowly defined clinical picture to a spectrum of conditions of uncertain similarity.” They warn that this blurring of the line could potentially make it more difficult to study the disorder.

Mottron, for his part, says the research points to a rampant problem of overdiagnosis that he blames on schools, doctors and parents alike. He goes so far as to suggest that a diagnosis can work in a school or parent’s best interest by making them eligible for extra help and funding that they may otherwise not receive.

“Right now, a diagnosis of autism is what allows one to get services in schools,” he said. “When you have an autism diagnosis, you have much greater chances of getting all kinds of extra things compared to another condition, which is total nonsense, because the need for services is independent from a diagnosis.”

He said the criteria for a diagnosis have become “trivial,” including a child’s lack of friends or a dislike of haircuts or tags on clothing.

Mottron acknowledged that the situation is complicated because mild forms of autism do exist. However, he noted that having certain autistic traits isn’t the same as having autism and said it’s “fundamental” for medical professionals to move beyond a simple checklist of symptoms before issuing a diagnosis.

He said the potential for misdiagnosis is problematic in many ways, including the risk of children receiving the wrong treatment.

RELATED: Amazon removes books that promoted autism ‘cure’

“The people who are diagnosed as autistic when they aren’t often have problems, but they’re not the same ones,” he said.

He said the cost of specialized services for autism are high and too many diagnosed children can spread resources too thin, meaning those who need them most don’t get enough.

Jean-Benoit Legault, The Canadian Press

Like us on Facebook and follow us on Twitter

Just Posted

Police officers and their dogs undergo training at the RCMP Police Dog Services training centre in Innisfail, Alta., on Wednesday, July 15, 2015. Mounties say they are searching for an armed and dangerous man near a provincial park in northern Alberta who is believed to have shot and killed a service dog during a police chase. THE CANADIAN PRESS/Jeff McIntosh
RCMP search for armed man in northern Alberta after police dog shot and killed

Cpl. Deanna Fontaine says a police service dog named Jago was shot during the pursuit

Alberta now has 2,336 active cases of COVID-19, with 237 people in hospital, including 58 in intensive care. (Black Press file photo)
Red Deer down to 73 active cases of COVID-19, lowest since early November

The Central zone has 253 active cases of the virus

The Sylvan Lake Gulls show off the home jerseys (white) and their way jerseys at the Gulls Media Day on June 17, before the season opener. Following the media day, the team took to the field for their first practise. (Photo by Megan Roth/Sylvan Lake News)
Sylvan Lake Gulls ready to throw first pitch as construction continues

The Gulls inaugural season kicks off June 18 with a game against the Edmonton Prospects

People line up to get their COVID-19 vaccine at a vaccination centre, Thursday, June 10, 2021 in Montreal. THE CANADIAN PRESS/Ryan Remiorz
Vaccines, low COVID case counts increase Father’s Day hope, but risk is still there

Expert says people will have to do their own risk calculus before popping in on Papa

Canadian Prime Minister Justin Trudeau is seen during a joint news conference following the EU-Canada Summit, in Brussels, Belgium, Tuesday June 15, 2021. Trudeau says Canada is on track now to have 68 million doses delivered by the end of July, which is more than enough to fully vaccinate all 33.2 million Canadians over the age of 12. THE CANADIAN PRESS/Adrian Wyld
Vaccine deliveries enough to fully vaccinate all eligible Canadians by end of July

Three in four eligible Canadians now have their first dose, nearly one in five fully vaccinated.

Chief Public Health Officer Theresa Tam listens to a question during a news conference, in Ottawa, Tuesday, Jan. 12, 2021. The number of confirmed COVID-19 cases attributed to the highly contagious Delta variant grew in Canada this week. THE CANADIAN PRESS/Adrian Wyld
Canada’s public health agency reports spike in confirmed cases of Delta variant

More than 2,000 cases of the variant confirmed across all 10 provinces and in one territory

The federal government says it wants to ban most flavoured vaping products in a bid to reduce their appeal to youth. THE CANADIAN PRESS/AP-Craig Mitchelldyer
Health Canada proposes ban on most vaping flavours it says appeal to youth

If implemented, the regulations would restrict all e-cigarette flavours except tobacco, mint and menthol

The Montreal Police logo is seen in Montreal on Wednesday, July 8, 2020. Some Quebec politicians are calling for an investigation after a video was released that appears to show a Montreal police officer with his leg on a young Black man’s neck during an arrest. THE CANADIAN PRESS/Paul Chiasson
Probe called for after video appearing to show Montreal officer’s knee on Black youth’s neck

Politicians call for investigation after clip evokes memories of George Floyd incident

Thousands of protesters make their way through the downtown core during a Black Lives Matter protest in Ottawa, Friday June 5, 2020. THE CANADIAN PRESS/Adrian Wyld
MPs’ study of systemic racism in policing concludes RCMP needs new model

Chair of the House public safety committee says it’s time for a reckoning on ‘quasi-military’ structure

A case filled with packages of boneless chicken breasts is shown in a grocery store Sunday, May 10, 2020, in southeast Denver. THE CANADIAN PRESS/AP-David Zalubowski
One million chickens euthanized during labour dispute at Quebec slaughterhouse

Premier says waste amounts to 13 per cent of the province’s chicken production thrown in the garbage

A section of the eastern slopes of the Canadian Rockies is seen west of Cochrane, Alta., Thursday, June 17, 2021. A joint federal-provincial review has denied an application for an open-pit coal mine in Alberta’s Rocky Mountains, saying its impacts on the environment and Indigenous rights aren’t worth the economic benefits it would bring. THE CANADIAN PRESS/Jeff McIntosh
Panel says Grassy Mountain coal mine in Alberta Rockies not in public interest

Public hearings on the project in southern Alberta’s Crowsnest Pass region were held last fall

The border crossing into the United States is seen during the COVID-19 pandemic in Lacolle, Que. on Friday, February 12, 2021. THE CANADIAN PRESS/Paul Chiasson
U.S. border restrictions to remain in place until at least July 21

Safety minister says Canada, U.S. extending restrictions on non-essential international travel

Most Read