Autism has nearly tripled in kids and young adults in the last decade – as researchers explain why
Data shows that autism in children and young adults in America has increased dramatically over the past decade.
An analysis of millions of health records found that the rate of diagnoses among all age groups rose 175 percent between 2011 and 2022, from 2.3 to 6.3 per 1,000 people.
The largest increase occurred among young adults aged 26 to 34, with an increase of 450 percent.
But children aged five to eight are still the most likely group to be diagnosed – at a rate of 30 per 1,000.
The researchers say better screening, greater awareness and broader diagnostic criteria are driving the surge.
But recent studies have also pointed to environmental factors such as pollution, and that aging mothers also play a role.
Researchers also noted that the ‘gender gap’ in autism is closing as more girls and women are diagnosed with the condition, which mainly affects school-aged boys.
A study published this week found that autism diagnoses increased by 175 percent between 2011 and 2022, likely due to increased screening, especially in adults, girls and women.
The graph above shows the increase in autism diagnoses between 2011 and 2022 by age group
But they warned that the actual numbers are likely even higher than predicted because not all autistic children have access to screening and therapy.
They wrote: ‘The figures reported here may underestimate the true prevalence of ASD in adults, especially older female adults, as many would not have been screened in childhood and would remain undiagnosed.
“Nevertheless, our findings indicate that the population of autistic adults in the US will continue to grow, underscoring the need for comprehensive health care services.”
However, other countries, such as Britain, are facing an even bigger increase. For example, a recent report from the NHS shows that 200,000 Brits are waiting for an autism assessment, an increase of 30,000 on last year.
According to the CDC, approximately one in 36 American children and one in 50 adults have autism.
Generally, most are diagnosed with the disorder by age five, although some can be tested as early as age two.
Although experts still don’t know what causes the condition, recent research suggests that environmental factors such as pollution, illnesses during pregnancy and older parental age may be to blame.
The latest study, published Wednesday in JAMA network openedlooked at 12.2 million Americans enrolled at 12 sites in the Mental Health Research Network, a group of U.S. mental health centers.
Of these, 77,683 were diagnosed with autism.
The majority of autistic participants were between the ages of zero and four, closely followed by the ages of five to eight.
The participants were then divided into age groups ranging from infants to 65 years and older.
Diagnoses decreased with age, with the smallest percentage (1 in 200) of the group being over 65 years of age.
Boys and men outnumbered girls and women three to one, which experts have suggested could be due to genetic mutations and hormones that are more common in boys.
The above graph shows the gap in autism diagnoses between men and women, indicating that diagnoses in women are overtaking those in men.
The researchers believe that the increase in diagnoses is due to “changes in developmental screening practices” for children and changes in “diagnosis definitions, policies, and environmental factors.”
Dr. Luke Grosvenor, lead author of the study and a postdoctoral fellow at the Kaiser Permanente Northern California Division of Research, said USA today that rising rates of autism in adults show that “we need to improve transition services for autistic individuals and their families.”
He noted that while autistic children often gain access to services such as speech therapy at school, they may lose access as adults. He said it is “critically important” that adults have access to these resources.
Other studies have suggested that environmental factors could be behind the surge.
For example, an Australian study published earlier this year found that boys exposed in utero to the endocrine-disrupting chemical Bisphenol A (BPA) were six times more likely to be diagnosed with autism before the age of 11 than boys without exposure.
That team suggested that BPA was associated with neurological and behavioral changes linked to autism.
Moreover, a Review 2021 found that “the odds of being diagnosed with autism were 3.3 times higher in premature individuals than in the general population,” because premature babies are vulnerable to birth complications and inflammation associated with autism.
This means that the increase in autism could be due to more premature babies surviving birth, as the survival rate has increased from 76 percent in 2008 to 2012 to 78.3 percent in 2013 to 2018, according to research from the National Institutes of Health (NIH).
The new study had several limitations, including diagnoses that were likely underestimated because the team relied only on diagnoses documented in medical records. The study also excludes patients without access to testing and doctors, such as those without insurance.
The team wrote, “Future work should characterize prevalence trends using these and other factors to represent individuals with varying levels of service needs and presentations of ASD.”