Have autism rates really tripled in the US or are doctors just getting better at spotting it?
The number of children with autism in the New York and New Jersey has tripled in 16 years, raising questions about whether the condition is becoming more common.
A study by researchers from Rutgers University found that between 2000 and 2016, the rate of Autism Spectrum Disorder (ASD) has increased from around one in 10 to around one in 30 children within the metropolitan area of New Jersey.
A similar rise is reflected nationally – rates increased from one in 150 children diagnosed with autism by the age of eight in 2000 to one in 54 in 2016, according to a CDC report published in 2021.
There is currently still no standard medical test for autism, but there have been big steps forward in diagnostic capabilities, as well as a greater understanding of the disorder, which seem to be driving the increase.
National autism rates in America have increased over time. Rates increased from one in 150 children diagnosed with autism by the age of eight in 2000 to one in 54 in 2016, according to CDC data
The graph above from the new Rutgers study shows autism prevalence estimates per 1,000 eight-year-old children in New Jersey overall and by intellectual ability. The proportion of eight-year-olds diagnosed with autism who do not have intellectual disabilities rose more steeply (shown by the blue line) than those who do not (shown by the green line)
The study, published in the journal Pediatrics, found that the proportion of eight-year-olds diagnosed with autism who do not have intellectual disabilities rose more steeply than those who do not – fivefold compared to twofold between 2000 and 2016.
The Rutgers team said the main reasons were advances in diagnosing, particularly in identifying autism without intellectual disabilities.
This refers to children who have an average or higher than average IQ as well as autistic traits such as trouble socializing and communicating, and doing the same things over and over.
These cases of autism might be harder to spot, as those with intellectual difficulties will be less able to carry out day-to-day tasks and so the disorder will be picked up more easily.
However, researchers are clear that the rise in prevalence of autism has nothing to do with vaccines.
Santhosh Girirajan, associate professor at Pennsylvania State University, told NBC News: ‘We know for sure, for so many years now, that vaccines don’t cause autism.’
Other reasons for the rise include genetic and environmental factors, but the precise cause is unknown.
Numerous studies have shown that children born to older parents are more likely to have the disorder. Complications at birth also raise the risk.
The Rutgers study said universal autism screening at routine pediatric visits is needed to better identify cases of autism which are moderate to mild.
Because there is no standard test for the condition, doctors must rely on a child’s developmental history and behavior.
But experts say early intervention can make a huge difference, with early detection key in ensuring kids on the spectrum get the help they need.
To receive an official diagnosis, children must still see a trained professional, but the ASDQ questionnaire represents another step towards a standardized test for autism.
Screenings for ASD are advised at the 18-month and 24-month milestones, whereby the child’s language, movement, and thinking skills, as well as behaviors and emotions, are tracked against the rest of their age group.
Formal diagnosis, however, must be handled by a trained specialist such as a developmental pediatrician or child psychologist.
About one in 44 children in the US has autism, a number that continues to rise as the disorder is de-stigmatized.
Despite scientific and social advancements, however, autism is still often only diagnosed well into childhood.
While the average age of diagnosis in the US is four years old, in the UK it is even older, at six.
What is autism?
What does being autistic mean?
Being autistic does not mean you have an illness or disease. It means your brain works in a different way from other people.
It’s something you’re born with or first appears when you’re very young.
If you’re autistic, you’re autistic your whole life.
Autism is not a medical condition with treatments or a ‘cure’. But some people need support to help them with certain things.
Autistic people may:
find it hard to communicate and interact with other people
find things like bright lights or loud noises overwhelming, stressful or uncomfortable
find it hard to understand how other people think or feel
get anxious or upset about unfamiliar situations and social events
take longer to understand information
do or think the same things over and over
What causes autism?
It’s not clear what causes autism.
Nobody knows what causes autism, or if it has a cause. It can affect people in the same family. So it may sometimes be passed on to a child by their parents.
Autism is not caused by:
- bad parenting
- vaccines, such as the MMR vaccine
- an infection you can spread to other people