A comprehensive study published in JAMA Network Open reveals that autism diagnoses in the United States have nearly tripled over just eleven years, with particularly significant increases among young adults and females.
Researchers from Kaiser Permanente's Division of Research analyzed data from over 12 million patients enrolled in major U.S. healthcare systems, finding that autism diagnoses increased by 175% between 2011 and 2022. This substantial rise coincides with the latest CDC report showing autism now affects approximately 1 in 31 American children, up from 1 in 36 in 2020.
Young Adults Show Most Dramatic Increase
The most striking finding was among young adults aged 26 to 34, who experienced a 450% increase in autism diagnoses during the study period. This more than five-fold rise suggests significant improvements in recognizing autism spectrum disorders (ASD) beyond childhood.
"The population of autistic adults in the U.S. will continue to grow, underscoring a need for expanded health care services," noted the research team led by Luke Grosvenor of Kaiser Permanente.
Gender Gap Narrowing in Autism Diagnoses
While autism remains more frequently diagnosed in males, the study revealed a significant shift in the gender distribution of new diagnoses. Among children, diagnoses increased by 185% for boys but soared by 305% for girls. Similarly, adult women saw a 315% rise in autism diagnoses compared to a 215% increase among men.
Researchers suggest this narrowing gender gap may reflect changing social dynamics and improved diagnostic practices. The study authors pointed to research indicating that females often "socially hide autistic traits" through a process known as "camouflaging," which may have previously led to underdiagnosis.
Factors Driving the Increase
Multiple factors appear to be contributing to the rising prevalence of autism diagnoses:
- Increased advocacy and public education about autism spectrum disorders
- Improved developmental screening practices for children
- Evolving diagnostic criteria and definitions
- Reduced social stigma surrounding neurodevelopmental conditions
- Greater awareness among healthcare providers
Dr. Carmen Pope, who reviewed the findings, emphasized that "the data could still be an undercount of cases of autism spectrum disorders, especially among adults."
Current Prevalence and Demographics
Autism rates remain highest among young children, with approximately 30 out of every 1,000 children ages 5 to 8 having an autism diagnosis. The CDC's latest report also indicates higher rates among boys and children who are Asian/Pacific Islander, Black, or American Indian/Alaska Native.
The historical context is striking—until the 1990s, autism was considered rare, with diagnoses typically limited to children with severe symptoms. The diagnostic umbrella has since expanded to include a range of conditions across the autism spectrum.
Scientific Consensus Amid Ongoing Questions
While some continue to question the causes of autism, the scientific consensus has firmly ruled out childhood vaccines as a factor. Researchers have instead focused on genetics, parental age, maternal health, and potential environmental exposures as areas for investigation.
The recent announcement by U.S. Health Secretary Robert F. Kennedy Jr. of a major autism research initiative has drawn criticism from the scientific community, particularly regarding the appointment of Dr. David Geier to lead the research—an individual who has promoted debunked theories linking vaccines to autism.
Healthcare Implications
The substantial increase in autism diagnoses across all age groups highlights the growing need for specialized healthcare services, educational support, and community resources. As more adults receive diagnoses, healthcare systems will need to adapt to provide appropriate care throughout the lifespan.
"Rates 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 remain undiagnosed," the researchers noted, suggesting the actual prevalence may be even higher than current statistics indicate.
