Despite high-profile claims from U.S. health officials that an autism "epidemic" is underway, a large population-based study out of South Korea tells a different story. Researchers screened over 62,000 seven-year-olds who started school between 2005 and 2017, finding that autism prevalence held steady across all cohorts — with no significant rise detected over the study period.

The study's strength lies in its methodology. Because elementary education is mandatory in South Korea with virtually no homeschooling, researchers were able to screen nearly every child in the country at school entry — capturing kids who had never sought autism-related services and providing a far more complete picture than clinical or administrative records alone.

By the Numbers:

• Autism cumulative incidence ranged from 1.9% to 3.2% (median 2.4%) across cohorts
• Prevalence ranged from 2% to 3.4% (median 2.5%), with no significant change from the 1998 to 2010 birth cohorts
• 62,081 children screened; 447 received an ASD diagnosis
• Boys had higher rates than girls (incidence range: 2.2%–4.8% vs. 1.5%–2%)

Why it matters: Experts say the real driver of increased autism diagnoses is improved awareness and expanded diagnostic criteria — not a true rise in autism occurrence. For clinicians and policymakers, this distinction is critical to ensuring that public health responses are grounded in evidence rather than misinformation.