South Korean study suggests stable autism rates reflect improved detection, not an epidemic

A comprehensive study in Goyang, South Korea, indicates that rising autism figures may be due to better screening rather than a true increase in cases, challenging assumptions of an autism epidemic.

A new South Korean study is adding weight to the argument that rising autism figures may reflect better detection rather than a true surge in cases. Researchers who screened first-grade children in Goyang, a satellite city north-west of Seoul, over 12 school years found that autism rates stayed broadly steady across 12 consecutive birth cohorts, with no meaningful rise or fall in either cumulative incidence by age 7 or prevalence at age 7. The findings were published in JAMA Pediatrics.

The research team, led by Young Shin Kim of the Dell Medical School at the University of Texas at Austin, used the same active screening approach each year between 2005 and 2017, with one year skipped. More than 62,000 children born between 1998 and 2010 took part. Of those who screened positive, 881 completed diagnostic assessments and 447 were diagnosed with autism spectrum disorder. The seven-year cumulative incidence ranged from 1.9% to 3.2%, while prevalence at age 7 ranged from 2.0% to 3.4%.

That stability matters because the study did not rely on service records alone. Instead, it systematically screened entire school cohorts, reducing the influence of shifting awareness, access to specialists and family willingness to seek an evaluation. The authors said the pattern supports improved detection as the main explanation for higher reported autism numbers and does not fit claims of an autism epidemic.

Still, the study has clear limits. It was conducted in a single city in South Korea, so its results cannot be assumed to apply directly to the United States, where diagnostic pathways, school systems and access to care differ. Fewer than half of the children who screened positive completed full assessment, which could affect precision, and the work does not address what causes autism or rule out changes in risk in other populations.

The findings arrive as autism remains a politically charged issue in the United States. The Centres for Disease Control and Prevention says about 1 in 31 children, or 3.2%, have been identified with autism by age 8 in its latest surveillance data, a figure that sits within the range seen in the Korean study. But local U.S. estimates vary widely, from 9.7 per 1,000 children in one Texas site to 53.1 per 1,000 in part of the San Diego area, underscoring how much identification depends on screening, referrals and services rather than geography alone.