Another 2015 study examined students in U.S. special education programs between 2000 and 2010. The number of autistic children who enrolled in special education tripled from 93,624 to 419,647. In the same time frame, however, the number of children labeled as having an “intellectual disability” declined from 637,270 to 457,478. The shift of children from one diagnostic category to another explained two thirds of the increase in autism in this population, researchers say.

https://www.scientificamerican.com/article/the-real-reason-a...

Some portion of the rise in autism rates may be unrelated to better diagnosis. The likelihood of having an autistic child increases for older parents, and there is a societal trend toward delaying childbirth across developed countries. Children who are born prematurely are also at a heightened risk of autism, and improved neonatal care means many more of these children are surviving to childhood and beyond.

As Secretary of Health and Human Services, Kennedy promised “some” of the answers to the causes of autism by September. But his “start from scratch” approach largely ignores research that has already been done. For example, Kennedy told reporters the initiative would look at ultrasounds during pregnancy as a possible risk factor. But a comprehensive multisite study of more than 1,500 pregnancies that found no link between autism and ultrasound use was published as recently as 2023. And scientists definitively ruled out the measles, mumps and rubella (MMR) vaccine as a cause of autism a decade ago (and again in 2019). In addition, the primary study that had suggested a link between the MMR vaccine and autism was found to have falsified data. Despite this, federal officials said in March that the Centers for Disease Control and Prevention will conduct a study to investigate a link between vaccines and autism. The study will be led by a vaccine skeptic who was previously disciplined for practicing medicine without a license.

https://www.statnews.com/2025/03/26/rfk-jr-vaccine-study-of-...