President Trump was surrounded by key medical officials in his administration including the Secretary of Health and Human Services on September 22, 2025, when he implied that taking acetaminophen (Tylenol) during pregnancy causes autism: “… acetaminophen which is basically commonly known as Tylenol during pregnancy, can be associated with a very increased risk of autism.”[1]

Additionally, the president suggested a new potential “treatment” for autism: “The FDA will be updating the label of an existing drug to reflect potential benefits in reducing some autism symptoms. This gives hope to the many parents with autistic children, that it may be possible to improve their lives.” [2] The “drug” mentioned is leucovorin (folinic acid), which is a prescription form of folate (vitamin B9).

Ironically, rather than being a recent “breakthrough,” B vitamin therapies actually have a venerable history as a potential autism treatment. More than 35 years ago. Mary Coleman, a pioneering autism researcher, reporting on Vitamin B therapies for autism, noted: “One of these therapies (vitamin B6) does appear to help some symptoms [of autism] in some patients.”[3] This does seem quite similar to the president’s statement that leucovorin (vitamin B9) “reflects potential benefits in reducing some autism symptoms.” The current paucity of strong evidence for the benefits of this drug is reflected in a 2025 review of leucovorin treatment for autism indicating that studies were based on “small sample sizes and modest mean differences” and noting, "folinic acid administration has the potential to reduce ASD symptoms in children. Further research with a larger sample size is needed to generalize the clinically meaningful results.” [4] [emphasis added] Although this may indeed be a promising medical therapeutic, the data are certainly not conclusive at this point as many studies show that B vitamins may—or may not—be beneficial for autism.

It is also worth mentioning that focusing on possible marginal benefits for leucovorin is dismissive of the hundreds of studies showing that developmental-behavioral interventions provide positive effects for improving “autism symptoms." These are widely available and are often far more effective than the marginal and inconsistent effects currently reported for leucovorin.[5]

Subsequent to the press conference on September 22, statements from groups such as the Society of Developmental and Behavioral Pediatrics (SDBP), which includes pediatricians specifically trained to assess and treat children with developmental disabilities such as autism (I am a nonphysician member of this society), and the advocacy group Autism Speaks (I have provided scientific........

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