“The first reason I think we are seeing an increase in autism is that what we used to call autism in the past has changed. We were only really picking up the more severe kids and we thought that autism was just one condition,” she says.
“We now know that autism is a lot of things - a body of conditions and we recognise as a spectrum”.
“And we weren’t picking up either end of the spectrum, so kids with severe intellectual disability didn’t used to get picked up and at the other end, kids who were very verbal and cognitively able but still quirky, also weren’t picked up.”
“So autism is a much broader spectrum than we realised and now we pick up both ends, so of course the numbers have increased.”
In other words, our understanding of autism has improved over time.
Medical advancements were another reason for the rise in autism diagnosis, according to Professor Dissanayake.
With better survival rates for premature babies, there were more children born at risk of autism, she says.
“Anything that affects the developing brain is a risk for autism and being born premature is a risk factor.”
The increasing age of fathers has also been repeatedly identified as another factor leading to an increase in autism diagnosis, says Professor Dissanayake.
“We used to think maternal age was linked to autism but it is much more likely that paternal age is a greater risk factor.”
How is autism diagnosed?
Diagnosing a child with autism can be tricky, because there is no blood test or scan that can help. Instead it is based on criteria related to observing the child and learning about their developmental history.
Professor Dissanayake says it is parents and carers who have the best insights into whether or not a child needs to be assessed.
“Parents should always act on their instinct and if they think something isn’t right then they should get their child assessed,” she says.
There were two core areas health professionals looked at when making an autism diagnosis. They are:
- Social communication and a child’s ability to communicate in a reciprocal way with other people.
- Restricted or repetitive behaviour or interests like having to do the same things in the same way over and over again, or getting upset when things aren’t done the same way every time.
Professor Dissanayake says autism occurs across a range of cognitive abilities.
A child health nurse or GP could be the first port of call for support, but ultimately a paediatrician should organise an assessment of the child.
“I can’t stress enough that a parent shouldn’t wait and see if their child will improve in certain areas, you know your child best and if you have concerns go and see your GP and get a referral to a paediatrician. If the GP doesn’t think you need one and you still have concerns then go elsewhere,” she says.
“It is really important that the child accesses early intervention and that parents and educators are supporting that child in similar ways across all of their activities,” she says.