US president Donald Trump has launched a broad offensive against the mainstream understanding of autism, claiming without new evidence that acetaminophen – the active ingredient in the common pain reliever paracetamol – was a cause of the disorder.
After months of widely trumpeted investigations spearheaded by the health secretary, Robert F Kennedy Jr, Donald Trump announced that pregnant women should limit their use of acetaminophen.
He claimed the painkiller, which is usually branded as Tylenol in the US and commonly known as paracetamol in Europe, heightens the risk of autism when it used by pregnant women, an assertion hotly contested by scientists internationally and contradicted by studies.
Speaking from the White House, flanked by Mr Kennedy, the president said he had “waited for 20 years for this meeting ...” and added: “It’s not that everything’s 100 per cent understood or known, but I think we’ve made a lot of strides.”
RM Block
But he declared: “Taking Tylenol is not good ... All pregnant women should talk to their doctors about limiting the use of this medication while pregnant.”
Mr Kennedy followed, announcing that the health department and US Food and Drug Administration would work to change the label on acetaminophen risks.
He also spoke about upcoming recommendations that the hepatitis B shot, currently given to newborns as part of the national vaccine standards, should be given in a delayed manner or in smaller doses, despite limited evidence of the impacts.
The announcements were made by Mr Trump amid a blaze of fanfare at the White House, in a ceremony attended by other senior administration figures.
Mr Trump – who has frequently voiced his concern over autism and said, along with Mr Kennedy, that the US is suffering from an “epidemic” – flagged up a major initiative on Sunday at Charlie Kirk’s memorial in Arizona.
“Tomorrow we’re going to have one of the biggest announcement[s] ... medically, I think, in the history of our country,” he said. “I think you’re going to find it to be amazing. I think we found an answer to autism.”
One in 31 children aged eight had a diagnosis of autism spectrum disorder (ASD) – a condition denoting communication and social difficulties, along with repetitive behaviours – in the US in 2022, according to the US Centers for Disease Control and Prevention (CDC). That compares with about one in 150 in 2000.
Mr Kennedy, who previously peddled the theory that the condition is caused by vaccinations, has attributed the rise to “environmental toxins”.
However, specialists say the increase is mainly due to increased screening, combined with evolving definitions of the disorder. They have also said the causes are predominantly dictated by genetics.
Scientists in the US and UK reacted to the Tylenol link sceptically, with British physicians denouncing it as “fearmongering” that risked stigmatising parents of children with autism.
Speaking on a call organised by Defend America Action, a campaign group, Debra Houry, a former chief medical officer and deputy director at the CDC, told journalists: “As of three weeks ago, we hadn’t seen evidence that acetaminophen was linked with autism, so it’s curious to know how quickly that was developed.”
“There are many studies which refute a link, but the most important was a Swedish study of 2.4m births published in 2024 which used actual sibling data and found no relationship between exposure to paracetamol [known in the US as acetaminophen] in utero and subsequent autism, ADHD or intellectual disability,” said Dr Monique Botha, associate professor in social and developmental psychology at Durham University
“The fearmongering will prevent women from accessing the appropriate care during pregnancy.”
US medical practitioners also cast doubt on the putative link with acetaminophen.
Dan Jernigan, another former CDC career scientist and former director of the national centre for emerging and zoonotic infectious diseases, criticised Mr Kennedy’s efforts to study autism.
“We were all asked to be a part of autism studies and to put together [an autism plan],” he said. “We helped develop some of that. But then over time, what we saw was [Kennedy] having an increasingly top down approach, essentially ‘my way or the highway’, with no regard again for the scientific processes.”
Some researchers have also pleaded caution on hopes for leucovorin, which has been reportedly shown in some tests to trigger marked improvements in the speaking and understanding ability of some people with autism.
Irva Hertz-Picciotto, an epidemiologist and autism specialist at the University of California, Davis, told the Washington Post that unrealistic expectations could lead to a loss of trust.
“I worry that it feels like everything is now tainted that comes out of the current administration,” she said.
Bruce Mirken, communications co-chair of Defend Public Health, poured cold water on the announcements in advance. “While we don’t know what he will claim today, we do know that Kennedy has a history of false statements related to autism and that the scientific evidence shows there is no ‘autism epidemic’,” he said. – Guardian
