Autism: Why are so many children being diagnosed these days?

When Lára Ní Riain began teaching almost 20 years ago, autism was still seen as a relatively rare condition.
There were no special classes or special-needs assistants (SNAs) at her school. Studies at the time suggested the prevalence of autism in Ireland was somewhere around seven in 1,000 schoolchildren.
Today, her school has seven SNAs as well as an autism-specific class for children with more complex needs. Studies now suggest as many as one in 20 schoolchildren may have autism or a similar developmental issue.
“Children are being diagnosed earlier now,” says Ní Riain. “It’s not about labelling students. Nowadays, knowledge is power — it’s about accessing all the support and expertise they require to give them the best chance at their education.”
So, why are so many more children being diagnosed with autism spectrum disorders compared with 20 years ago?
The latest official estimate on autism prevalence in Ireland was gathered in 2022 by the National Council for Special Education, which collects data on the number of children who require teaching support.
It indicates there was a prevalence rate of 3.4 per cent among schoolchildren, a significant change from the previous estimate of just under 1.6 per cent four years earlier.
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In Northern Ireland, the estimates are higher still. Health authorities reported in 2023 that 5 per cent, or one in 20 schoolchildren, had a diagnosis of autism. It is more than four times as many as 15 years ago — and one of the highest rates recorded in the world.
On the face of it, the surge in autism looks alarming and has sparked a series of unfounded claims that vaccines or other environmental factors may be at play.
Increases in diagnoses, however, have been a feature of autism for almost as long as it was first described as a recognised condition by Dr Leo Kanner in the United States in 1943.
So, too, have discredited theories behind the cause of the condition, such as “refrigerator” or emotionally cold mothers and, more recently, Dr Andrew Wakefield’s unfounded claims of a link with the MMR vaccine.
Most experts today agree that the exponential rise is chiefly down to greater awareness, deeper understanding of the condition and ever-wider assessment boundaries for autism.
“There is absolutely no evidence to suggest there is an epidemic of autism,” says Prof Emer Ring, dean of education at Mary Immaculate College in Limerick and author of a recent book on the development of special education in Ireland over the past 100 years. “It’s a no-brainer that as you broaden diagnostic criteria you will have more children with autism.”
Some of the confusion around autism is undoubtedly linked to the complexity of the condition.
There is no medical test or biological marker for autism. Today, it is regarded as a developmental disability which influences how a person communicates with and relates to other people and how they make sense of the world. It is also regarded as a spectrum condition, as it affects people in different ways and to varying degrees.
Prof Malcolm MacLachlan of Maynooth University, who had studied the prevalence of autism in the Republic, agrees that changes in the criteria used to diagnose a person are key to the increased prevalence of autism.
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Asperger’s syndrome, for example, was removed as a diagnosis in the Diagnostic and Statistical Manual of Mental Disorders — often referred to as “psychiatry’s bible” — in 2013 and has been integrated into a broader diagnosis of autism spectrum disorder.
“There used to be ridiculously strict criteria,” MacLachlan says. “For instance, it used to be that you had to have detected autism before the 30th month of life — now you can detect it at any time. There’s also now a move away from ‘you have it or you don’t’ categories to a more dimensional approach that allows people to have more ‘severe’ or less ‘severe’ behaviours or experiences.”
Shifting boundaries encompass a wide range of people for whom autism would never have been considered as a possible diagnosis, especially women and girls. The consequent awareness has led to large numbers of adults seeking medical referrals to explain differences they may have been aware of since childhood.
Another factor, say many, is the neurodiversity movement of the late 1990s and early 2000s, which drove huge changes in identification, fighting stigma and redefining autism as an identity rather than a disease.
More controversial, meanwhile, is a belief that a diagnosis can unlock access to improved services or supports. A government report in 2018 on autism prevalence pointed out that, in many countries — including Ireland — a diagnosis of autism gives children greater access to a special school or special class.
“This benefit makes clinicians more likely to diagnose a child with autism, even those who are on the borderline of the clinical criteria,” the report notes.
For campaigners, the increase in prevalence is a positive development. Adam Harris, chief executive of autism charity AsIAm, says a diagnosis is “vital to self-understanding, self-esteem and self-advocacy and enables an autistic person and their family to understand their support needs and have their rights vindicated by government and broader society.
“It is clear that increased diagnosis of autism must lead to increased funding and more effective forward planning for autism-specific services,” he says.
The dramatic increase in autism begs another question: where were all these children in the classroom of days gone by? Some were segregated within the system, institutionalised or, at worst, classed “ineducable”; others simply had different labels.
Ring points to the work of Dorothy Bishop, a prominent British psychologist, whose research has examined how in adulthood some individuals with language problems were retrospectively found to have shown signs of autism as children, even if they were not diagnosed at the time. Her work, says Ring, highlights the complexity and variability in diagnosing autism, especially in individuals with subtle symptoms.
As for the underlying causes of autism, there is growing evidence which suggests that certain genes contribute to it. Autism can run in families and experts have put its “heritability” at about 80 per cent, or about as heritable as height or eye colour. The condition may also be explained by rare but powerful mutations that occur at random and are unrelated to genes that run in families. There is less convincing evidence around other risk factors, such as low birth weight or older parents.
What is certain, however, is that rates are rising, which will have profound implications for how the State meets the needs of young people, especially, in education and health services.
Health Service Executive services, however, are creaking. Under the Disability Act (2005), health authorities are required to complete an assessment of a child within six months.
Yet, according to records obtained by The Irish Times, there are about 13,000 children with disabilities waiting for an “initial contact” — which can be anything from a phone call explaining services or setting agreed goals — by health services. Of these, more than 9,000 — or two out of three — are waiting for more than 12 months.
Parents, professionals and other stakeholders say that in many cases children are waiting several years for any meaningful contact. Yet, experts agree early intervention is vital to securing positive outcomes for children during their preschool and early-school years.
MacLachlan says long waits for access to vital therapeutic services can have “catastrophic” long-term consequences for children.
“If a child is going through a critical developmental period and they don’t get the right critical interventions, the consequences may not just be a delay in that developmental stage, it may be a long-term loss of opportunity to develop particular skills,” he says.
Education services, too, are struggling. In the last five years alone, almost 1,700 special classes have been opened and eleven new special schools opened. Yet, many parents are unable to find appropriate school places — such as special classes or schools — to meet their children’s assessed needs.
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Latest figures show there are more than 8,000 children enrolled in special schools and a further 11,000 pupils in special classes in mainstream schools, or 3 per cent of the overall student population. This is projected to climb to 5 per cent by the end of this decade, based on current trends.
Harris says the next government must take decisive actions to support the autistic community.
“Autistic people continue to face pervasive barriers in day-to-day life in Ireland, from receiving timely assessment and therapeutic support to accessing school, to participating in the community and securing employment,” he says. “The barriers which our community face place enormous costs on our community, which in turn impact on health and wellbeing.”
In the longer term, the National Council for Special Education has urged that we move towards a “fully inclusive” school system where all students — regardless of their conditions — would be educated in mainstream schools.
The council says such a goal would involve significant challenges, such as reassuring parents of the benefits of an inclusive education system, increasing access to psychological and therapeutic supports and boosting training for teaching staff.
Ring agrees that this is the way forward, especially a school system where therapeutic supports — such as speech and language therapy — are delivered in the school itself.
“Special education cannot advance in isolation,” she says. “It must be a key element of our education, health, social, culture and economic policy. We need all the organs of the State working together.”
For now, it is a pipe dream. In Dublin 15, where pressure is most acute for appropriate school places, school principals would settle for basic supports.
Principals across 37 primary schools in the area estimate that more than 100 children with autism and other conditions are struggling in their mainstream school placements.
“Without adequate supports, these placements will most likely negatively impact the wellbeing and mental health of these students, the health and safety to peers and school personnel and ultimately put the student’s school placement at risk,” a report prepared by the Dublin 15 Primary Principals’ Network states.
Ní Riain says while supports at her school have increased over recent years and great strides have been made, there are real challenges accessing therapeutic services which are vital to help vulnerable children reach their full potential.
“That’s a huge challenge,” she says. “When you have a student with complex needs, you can do all training you want, but it can be difficult to access outside support … I spend a lot of my time tormenting parents, getting them to fill in the same forms for different services. You are looking at five-year waiting lists. Even where families have the opportunity to go private, there’s usually still a waiting list.”
If there were multidisciplinary teams linked up with schools, she says, it would be a far more efficient use of resources.
Ultimately, for all the talk about autism prevalence rates and diagnoses, it shouldn’t matter; she says services for children should be based on their individual needs.
“If you’ve met one child with autism, you’ve only met one child with autism. Every learner is unique — all their needs are unique,” she says. “It’s very much about the relationship, getting to know the student. You do need to look beyond the disability or diagnosis. We’ve come a long way, with all children attending the same school [instead of being segregated]. That means the world to children and their parents.”