A recently published study has found that diagnoses of autism among young adults and children in the United States have grown considerably in the last decade, with the overall number of cases spiking nearly 200% in this period.
The analysis, published Wednesday in JAMA Network Open, reported that autism spectrum disorder spiked 175% among people in the US from 2.3 per 1,000 in 2011 to 6.3 per 1,000 in 2022.
Researchers in the study had set out to assess how many adults had been diagnosed with autism, as earlier studies were mainly focused on school-age children, said Luke Grosvenor, the study’s lead author and a postdoctoral fellow at Kaiser Permanente’s Northern California research division.
“There has been a shortage of research focused on autistic adults,” Grosvenor said.
Within the past two decades, four times as many children have been diagnosed with autism as screening processes and definitions have progressed, along with societal awareness regarding the condition. As of 2023, 1 in 36 children in the US have autism, up from the previous rate of 1 in 44, while 1 in 45 adults are diagnosed.
According to the JAMA network study, diagnoses climbed at a faster rate among adults in their mid-20s to mid-30s in the period they evaluated, reporting that rates of autism for adults ages 26 to 34 increased more than 450% from 2011 to 2022.
Grosvenor said the growing rates of diagnoses among adults show that “we need to improve transition services for autistic individuals and their families” when they enter adulthood. While children may be more likely to receive access to services such as speech therapy and other assistance in school, they often lose access to such care when they become adults, yet the need does not disappear, he said.
The JAMA network study also reported differences in autism rates by race, ethnicity and sex. Diagnoses were reported to be the highest among indigenous children and adults, and the increase in rates of autism was found to be greater among Black, Asian, Hispanic, Native American and Alaska Native children compared with white children.
Boys were found to still be more likely to be diagnosed with autism than girls. However, the study noted that autism diagnoses increased at a faster rate among girls than boys over the decade-long period of the research.
Dr. Alycia Halladay, chief science officer for the Autism Science Foundation, said the study’s estimates for adults are “enormously important” and draw attention to the need to track autism patients over time. She added the report also displays the value of harvesting information from medical records so researchers can provide a more detailed look at people with autism, and said she would like to see a study on adults with autism that addresses questions such as educational attainment and employment prospects.
