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

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Alberta had 1,571 active COVID-19 cases on Tuesday. THE CANADIAN PRESS
Alberta’s central zone now has 1,101 active COVID-19 cases

Provincial death toll has risen by nine

COVID-19. (Image courtesy CDC)
Alberta reports 1,731 new COVID-19 cases on Saturday

The province’s central zone has 992 active cases

(Photo submitted)
Ermineskin citizen graduates vet school, is part of busy practice

Dr. Justin Hodgson is rolling up his sleeves in Meadow Lake, Sask.

Shaela Dansereau/Pipestone Flyer
Wetaskiwin City services impacted by new public health measures

Public centers and availability to public impacted by the new public health measures.

Idyllic winter scenes are part of the atmosphere of the holiday season, and are depicted in many seasonal movies. How much do you know about holiday movies? Put your knowledge to the test. (Pixabay.com)
QUIZ: Test your knowledge of holiday movies and television specials

The festive season is a time for relaxing and enjoying some seasonal favourites

A B.C. Ambulance Service paramedic wearing a face mask to curb the spread of COVID-19 moves a stretcher outside an ambulance at Royal Columbia Hospital, in New Westminster, B.C., on Sunday, November 29, 2020. THE CANADIAN PRESS/Darryl Dyck
Top doctor urges Canadians to limit gatherings as ‘deeply concerning’ outbreaks continue

Canada’s active cases currently stand at 63,835, compared to 53,907 a week prior

A Canadian Pacific freight train travels around Morant’s Curve near Lake Louise, Alta., on Monday, Dec. 1, 2014. A study looking at 646 wildlife deaths along the railway tracks in Banff and Yoho national parks in Alberta and British Columbia has found that train speed is one of the biggest factors. THE CANADIAN PRESS/Frank Gunn
Study finds train speed a top factor in wildlife deaths in Banff, Yoho national parks

Research concludes effective mitigation could address train speed and ability of wildlife to see trains

A airport worker is pictured at Vancouver International Airport in Richmond, B.C. Wednesday, March 18, 2020. THE CANADIAN PRESS/Jonathan Hayward
Canada extends COVID restrictions for non-U.S. travellers until Jan. 21 amid second wave

This ban is separate from the one restricting non-essential U.S. travel

In this undated photo issued by the University of Oxford, a volunteer is administered the coronavirus vaccine developed by AstraZeneca and Oxford University, in Oxford, England. Pharmaceutical company AstraZeneca said Monday Nov. 23, 2020, that late-stage trials showed its coronavirus vaccine was up to 90% effective, giving public health officials hope they may soon have access to a vaccine that is cheaper and easier to distribute than some of its rivals. (University of Oxford/John Cairns via AP)
Moderna chairman says Canada near head of line for 20 million vaccine doses

Trudeau created a firestorm when he said Canadians will have to wait a bit to get vaccinated

Conservative MP Pierre Poilievre speaks during a news conference Monday, Nov. 16, 2020 in Ottawa. Poilievre says building up the Canadian economy post-pandemic can't be achieved without a massive overhaul of the tax system and regulatory regime. THE CANADIAN PRESS/Adrian Wyld
Conservatives attack Trudeau’s ‘reset’ but they have ideas for their own

‘We don’t need subsidized corporate welfare schemes that rely on endless bailouts from the taxpayer’

There were 47 new COVID-19 cases in Alberta Tuesday. (THE CANADIAN PRESS/Paul Chiasson)
Spread of COVID-19 in Brampton, Ont., linked to systemic factors, experts say

‘We’re tired. We’re numb. We’re overworked. We’re frustrated, because it’s not our rules’

A couple embrace during a ceremony to mark the end of a makeshift memorial for victims of the Toronto van attack, at Yonge St. and Finch Ave. in Toronto on Sunday, June 3, 2018. THE CANADIAN PRESS/Cole Burston
‘I’ve been spared a lot,’ van attack survivor says as she watches trial alone

Court has set up a private room for victims and families of those killed in the Toronto van attack

A person enters a building as snow falls in Ottawa, Sunday, Nov. 22, 2020. Ottawa has been successful in limiting the spread of COVID-19 during its second wave thanks to the city’s residents who have been wearing masks and staying home, said Ottawa’s medical officer of health Dr. Vera Etches. THE CANADIAN PRESS/Justin Tang
People to thank for Ottawa’s success with curbing COVID-19: health officer

The city’s chief medical officer said much of the credit goes to the people who live in Ottawa

Most Read