Tylenol, Autism, and the Breakdown of Scientific Communication

No one has more confidence than a rich, powerful white man who has absolutely no clue what he’s talking about.

In recent months, President Trump and Secretary Robert F. Kennedy Jr. have espoused a causal link between prenatal use of acetaminophen, the active ingredient in Tylenol, and the occurrence of autism and other neurodevelopmental conditions like ADHD. This connection is empirically unsupported. The Yale School of Public Health has stated that because autism is multifactorial and its exact determinants are unknown, it is premature to definitively identify a single cause. RFK Jr. has actually expressed similar nuance in the past, yet is now sowing distrust around a medication that has been used by millions of Americans for decades without significant adverse side effects.

Extra Strength Tylenol Pill Bottle, Flickr, 2013. Creative Commons License.

The justification for these claims, as well as RFK Jr’s skepticism around vaccines, seems to be the recent uptick in autism and ADHD diagnoses. FDA Commissioner Martin Makary has corroborated this association using observational studies, such as the Boston Birth Cohort and Nurses’ Health Study II. However, because Tylenol is over-the-counter and usage is self-reported, these studies are inconclusive. Another major confounder is that Tylenol use is usually motivated by an underlying condition, such as headaches due to abnormal blood pressure or fever, which can affect developmental outcomes.

I learned in middle school that correlation cannot be used to infer causation, yet that is precisely what these politicians are doing. They also equate the rise in diagnoses to higher prevalence of autism and ADHD, when it more likely reflects increased awareness and access. My ADHD was only diagnosed at age 20 because I had little knowledge of the diagnostic criteria outside of stereotypes until I learned more in my late teens via peers and the Internet. Once I decided to get assessed, I went through multiple providers to find one who accepted my insurance and was geographically accessible. Because diagnoses are so contingent on socioeconomic factors, counting them is an inaccurate way to quantify the neurodivergent population.

There is strong scientific evidence to suggest that the correlation between acetaminophen and neurodevelopmental disorders is illusory. A survey of 2.5 million children in Sweden found only a 0.09% difference between autism rates in the populations exposed and unexposed to acetaminophen during pregnancy, and no difference when sibling relationships were considered, suggesting that confounding factors explain most, if not all, of the correlation (Ahlqvist et al. 2024). Another sibling-controlled study of 200,000 children in Japan found no link (Okubo et al. 2025), and a recent review corroborated these findings (Damkier et al. 2025). The American Academy of Pediatrics concurs that there is no causal link between acetaminophen use and neurodevelopmental disorders when administered as recommended. This dosage relationship is essential; it applies to the fearmongering about the cancer-causing potential of artificial sweeteners based on rodent studies where animals were given megadoses that would be unrealistic for a human to consume. Tylenol can be toxic at high enough doses, but as with practically anything, the dose makes the poison.

Earlier this year, Trump went on another rant, asserting that scientists spent $8 million “making mice transgender”. The White House website lists the studies he was referencing and their budgets, absolutely none of which involved “making transgender mice.” In fact, all of these studies used animal models to study the effects of sex hormones on various health outcomes, including HIV vaccine efficacy and breast cancer treatment. Animal research is ethically complicated and has limited generalizability, but these studies are certainly not irrelevant to human health. Even a cursory glance at the actual papers reveals this, but many people simply don’t get that far–they get their news from the mouth of a politician or read it on the strikingly unprofessional White House website, which has a tone reminiscent of middle school cyberbullying.

The fearmongering around Tylenol is a small branch of a sprawling web of disinformation that has been growing rampantly thanks to a host of influential contributors, many in the highest ranks of government. They link sensationalized pseudoscience to people’s unconscious biases to undermine trust in scientific institutions and consolidate power. In the case of Tylenol, this strategy harms pregnant people who might ultimately forgo pain medication altogether, and anyone else who relies on these medications will suffer if access is restricted. It also hurts neurodivergent people, who already face intense societal stigma, just as demonizing basic research on sex hormones is socially harmful to trans people as well as directly limiting their access to gender-affirming care and putting them at risk of worse health outcomes. Neurodiversity is not necessarily pathological, and rather than treating it as a disease to be eradicated, we should aim to help neurodivergent people thrive and maximize our potential.

Politicians are not only misinforming the public, but presenting inconclusive scientific findings as absolute truth. The consensus among actual scientists is that science is rooted in critical thinking and constantly adjusting our paradigms to better reflect reality. “Facts” are approximations of the truth by individuals heavily influenced by their socioeconomic and cultural context. Many consider truth itself to be subjective, and even the scientists who believe in a single objective reality acknowledge that our understanding of it is imperfect, that there is always more to discover.

According to autism advocate James Cusack, “people are always seeking “simple answers to complex problems.” The Trump administration perfectly exemplifies this–they promote fear, censorship, and disinformation as a panacea for every issue plaguing our society. They use polarizing, inflammatory language, hacking away at the already tenuous lines of communication between scientists and the public. If this process continues unchecked, our society could easily slip into a new Dark Age.

The antidote to this campaign of pseudoscience is a sincere commitment to accurately informing the public, and while clarity of delivery is crucial, this process need not be emotionless. In fact, in order to combat the demagoguery of Trump and his associates, educators should infuse their communication with passion and stand firmly in defense of science and intellectual integrity. We cannot let the pursuit of truth be written out of the social contract. Our curiosity, our discernment, our sense of wonder–these qualities are central to our humanity. We must protect them as if our lives depend on it, because they do.

By Louisa Miller-Out 

References

Acetaminophen is Safe for Children When Taken as Directed, No Link to Autism. (2020). Aap.org. https://www.aap.org/en/news-room/fact-checked/acetaminophen-is-safe-for-children-when-taken-as-directed-no-link-to-autism/srsltid=AfmBOoqN1bzJDMJ3uE8TOujUzEBJsCs8g2tZWyoomPcpJ3DVSFzrqxS7

Burdick, A. (2025, October 8). Has Your Scientific Work Been Cut? We Want to Hear. The New York Times. https://www.nytimes.com/2025/10/08/climate/trump-climate-science-funding.html

Damkier, P., Gram, E. B., Ceulemans, M., Panchaud, A., Cleary, B., Chambers, C., Weber-Schoendorfer, C., Kennedy, D., Hodson, K., Grant, K. S., Diav-Citrin, O., Običan, S. G., Shechtman, S., & Alwan, S. (2025). Acetaminophen in Pregnancy and Attention-Deficit and Hyperactivity Disorder and Autism Spectrum Disorder. Obstetrics and Gynecology, 145(2), 168–176. https://doi.org/10.1097/AOG.0000000000005802

News. (2025, September 23). UC Davis MIND Institute statement on acetaminophen and autism. News; UC Davis Health. https://health.ucdavis.edu/news/headlines/uc-davis-mind-institute-statement-on-acetaminophen-and-autism-/2025/09

Office. (2025). FDA Responds to Evidence of Possible Association Between Autism and Acetaminophen Use During Pregnancy. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements/fda-responds-evidence-possible-association-between-autism-and-acetaminophen-use-during-pregnancy

Okubo, Y., Hayakawa, I., Sugitate, R., & Nariai, H. (2025). Maternal Acetaminophen Use and Offspring’s Neurodevelopmental Outcome: A Nationwide Birth Cohort Study. Paediatric and Perinatal Epidemiology, 10.1111/ppe.70071. https://doi.org/10.1111/ppe.70071

Pearson, H., & Ledford, H. (2025). Trump links autism and Tylenol: is there any truth to it? Nature.com. https://doi.org/10.1038/d41586-025-02876-1

Poitras, C. (2025, September 22). What the research says about autism and Tylenol use during pregnancy. Yale School of Public Health; Yale School of Medicine. https://ysph.yale.edu/news-article/what-the-research-says-about-autism-and-tylenol-use-during-pregnancy/

The White House. (2025, March 5). Yes, Biden Spent Millions on Transgender Animal Experiments. The White House. https://www.whitehouse.gov/articles/2025/03/yes-biden-spent-millions-on-transgender-animal-experiments/