Fearmongering, blaming mothers, and even talk of a so-called “magic cure for autism” were featured in controversial remarks by President Trump. He cited what critics called a “high-quality” science’ report, though outlets like The Guardian challenged its credibility.
During his speech, Trump described the rise in autism diagnoses as a “horrible crisis,” a topic he said he was “very concerned about.” He even spoke of an “autism epidemic” in the country. In fact, during an official broadcast, he declared: “I think we’ve found an answer to autism,” calling the announcement “one of the most important things we will ever do.”
The problem is that finding the cause of autism is anything but simple. The scientific community has spent decades studying this complex condition, and its explanation is far from straightforward or reducible to a single factor, as the White House seems to suggest.
However, Trump claims to have identified the root of the problem: according to him, the use of acetaminophen—also known as paracetamol, or by its most familiar U.S. brand name, Tylenol—during pregnancy is responsible for causing autism in children, especially in the later stages of gestation. This was even shared on the White House’s official website. But what was he basing this on?
On what evidence did Trump rely to assert that Tylenol causes autism?
To back up his claim, the White House cited, among others, four scientific studies. However, none of them demonstrates causation. In every case, what researchers found were statistical associations, with methodological limitations acknowledged by the authors themselves. So what does the evidence actually show? Here’s a breakdown:
This study measured acetaminophen biomarkers in umbilical cord blood and found that higher exposure was associated with an increased likelihood of autism and ADHD, even showing a dose–response pattern. But researchers were clear: this was only an observational link that “requires further investigation” and does not prove causation or rule out potential confounding factors.
- Nurse’s Health Study II
This study used a “negative control exposure” method to analyze the relationship between frequent acetaminophen use and ADHD. The authors emphasized that the results could be affected by unmeasured confounding and that the link was not conclusive. The article does not claim causation; on the contrary, it underscores the challenges of observational studies in pregnant populations when it comes to providing definitive answers.
- Systematic Review Using the Navigation Guide Method (Mount Sinai and collaborators, 2025)
This review synthesized the available evidence and rated the probable association between acetaminophen and ADHD as “strong,” while also reporting links to autism. However, it is still an analysis of observational studies and calls for more rigorous research before any conclusions can be drawn.
- Meconium Cohort (Baker et al., JAMA Pediatrics, 2020)
In this study, acetaminophen was detected in meconium samples, and researchers found a higher risk of ADHD along with alterations in brain connectivity. The authors themselves, however, stressed that their cohort was relatively small, with preliminary and observational results: it does not prove that the drug causes autism or ADHD.
So, what’s the takeaway? The conclusion is clear: none of these studies confirm that taking acetaminophen during pregnancy induces autism or ADHD. All of them report associations—some even showing a dose–response gradient—but with design limitations and residual confounding that prevent any claim of causation, as the authors themselves acknowledge.
Official and corporate reactions
Trump’s remarks had an immediate impact. Tylenol’s parent company flatly denied the allegations, but its stock price fell after the White House announcement, according to the BBC.
Secretary of Health Robert F. Kennedy Jr. announced that the FDA would issue an advisory to doctors about the “potential risk” of using Tylenol during pregnancy. He also signaled upcoming changes to the drug’s safety labels and a public awareness campaign.
In an official statement, the agency explained: “The FDA has initiated the process to update the labeling of acetaminophen (Tylenol and similar products) to reflect evidence suggesting that its use during pregnancy may be associated with a higher risk of neurological conditions such as autism and ADHD in children.”
In Europe, the Spanish Agency of Medicines and Medical Devices (AEMPS) pointed out that acetaminophen in Europe already carries a specific warning: “Epidemiological studies on neurodevelopment in children exposed to acetaminophen in utero show inconclusive results.”
Trump’s proposed “solution”: Leucovorin
During the same announcement, the Trump administration also suggested the use of leucovorin (folinic acid) as a possible response to autism.
The scientific evidence, however, is limited. Leucovorin has shown modest benefits in small trials with children diagnosed with autism and language difficulties, particularly in cases involving specific antibodies. But experts are clear: it neither prevents nor “cures” autism, and much larger studies are still needed before it can be recommended more broadly.
So, what does science really say?
In contrast to Trump’s certainty, the scientific community agrees that the evidence linking acetaminophen to autism is, at best, inconclusive. The prevailing view among researchers has a common thread: there is no single cause of autism. Instead, it is a complex condition that results from the interaction of multiple genetic and environmental factors.
The American College of Obstetricians and Gynecologists told the BBC that studies conducted in the past show no clear evidence of a direct link between the prudent use of acetaminophen in any trimester and fetal developmental problems.
A recent study published in JAMA examined whether taking acetaminophen during pregnancy increases the risk of autism, ADHD, or intellectual disability. At first glance, the population data seemed to show a slightly higher risk. But when scientists compared exposed and unexposed siblings within the same family, they found no significant increase.
No differences were observed based on dosage either: using a little, a moderate amount, or a lot did not change the results. In conclusion, acetaminophen use during pregnancy does not cause these developmental disorders. The supposed risk signals seen in earlier studies were most likely explained by family, genetic, or maternal health factors.
Researcher Angelica Ronald, Professor of Psychology and Genetics at the University of Surrey, told the SINC agency: “Twin studies show that if acetaminophen caused autism, both fraternal twins would have it. But that’s not the case: usually only one is affected. In addition, molecular research has identified hundreds of genes that influence the likelihood of developing autism, which is incompatible with the idea that acetaminophen is a primary causal factor.”
Psychologist Monique Botha of Durham University spoke about the risks of this kind of rhetoric: “Alarmism will only prevent women from getting the care they need and reignite the pattern of blaming mothers for autism.”
In fact, experts point out that acetaminophen is an important tool for managing fever and pain during pregnancy—symptoms that, if left untreated, can also pose risks to the fetus.
Meanwhile, the Spanish Agency of Medicines and Medical Devices (AEMPS) maintains that “there is no evidence linking the use of acetaminophen during pregnancy to autism in children in a causal way.”
The official recommendation remains: it can be used when necessary, always at the lowest effective dose and for the shortest possible duration.
An additional observation: there have been associations found between autism and the father’s age at conception; more specifically, the sperm of older men appears to increase the likelihood of autism in their children, according to at least three different studies. Nevertheless, Trump, 79, has made no comment or issued any warning on the matter.
Trump Administration vs. science
This isn’t the first time Donald Trump has departed from mainstream scientific consensus while relying heavily on his own beliefs. His political style often relies on sweeping statements, even when they lack empirical support, and this issue was no exception.
Added to this is the role of his Secretary of Health, Robert F. Kennedy Jr., a figure long known for his controversial positions against medical evidence. Long before joining the cabinet, Kennedy has previously promoted theories linking vaccines to autism, which have since been widely discredited. In particular, he repeatedly blamed vaccines for the rise in diagnoses, despite overwhelming evidence that no such link exists.
In 2005, RFK Jr. published an article titled Deadly Immunity in Rolling Stone and Salon, claiming that vaccines containing thimerosal were connected to autism and alleging a government conspiracy to cover it up. The article contained several factual errors. Salon issued five corrections and ultimately retracted the piece entirely in 2011. The retraction was justified by mounting criticism that the article had cited data out of context or in a misleading way.
Another so-called “report” backed by the Trump administration under RFK Jr.’s direction was promoted as “high-quality science,” but outlets like The Guardian have documented that some of its citations were studies that either do not exist or did not support the claims being made.
Kennedy Jr. has also been a frequent promoter of the idea that vaccines are linked to autism—an assertion widely discredited by the scientific community. In judicial nominations and hearings, he has defended positions that have been labeled as misinformation, and even his remarks about the immune system capacity of racialized groups in relation to vaccines have been called into question.
What’s more, the official went so far as to say that children diagnosed with autism would “never work, never pay taxes, never go on a date, play baseball, or find love.”
The current narrative—pointing to acetaminophen as a supposed “cause” and proposing leucovorin as a “magic cure”—fits the same pattern: reducing complex problems to quick, flashy solutions, even when they lack scientific backing.
By contrast, science stresses caution, evidence, and multicausality. Autism doesn’t have a single explanation or “culprit.” If only it were that simple. And while the safety of many medications during pregnancy—including acetaminophen—is being studied, the strongest research so far is unequivocal: there is no proof that acetaminophen causes autism or ADHD.
Cover photo by Foto de Erik Mclean on Unsplash (edited).
