The US government has announced new health recommendations concerning the prevention and treatment of autism in children. The guidance, issued by the Trump administration, discourages pregnant women from using the painkiller paracetamol, also known as acetaminophen or Tylenol, due to concerns about its potential link to autism. Additionally, the recommendations introduce the use of the drug leucovorin as a treatment for speech-related difficulties often experienced by children with autism.
Understanding Leucovorin
Leucovorin is a derivative of folic acid, a B vitamin typically obtained through foods such as legumes, citrus fruits, and fortified grains. It is primarily utilized in cancer treatment, enhancing the effects of the chemotherapy drug fluorouracil, which impedes cancer cell growth by disrupting DNA synthesis. Leucovorin also mitigates the toxic side effects of another chemotherapy agent, methotrexate, which inhibits the body’s use of folate necessary for DNA production. By providing an active form of folate, leucovorin allows healthy cells to continue their functions while methotrexate targets cancer cells.
The importance of folate in human health cannot be overstated. It is crucial for DNA synthesis and repair, making it particularly vital during pregnancy. Insufficient folate intake is associated with severe birth defects, such as spina bifida, leading to widespread recommendations for women to take folic acid supplements before conception and during early pregnancy. Moreover, folate plays a key role in red blood cell production and overall brain function.
Leucovorin’s Potential Role in Autism Treatment
The suggestion that leucovorin may assist children with autism arises from the theory linking low folate levels in the brain to a condition known as cerebral folate deficiency. Children with this deficiency often remain asymptomatic until around age two, when symptoms such as speech difficulties, seizures, and intellectual disabilities begin to emerge. Given that autism typically presents around the same age, some researchers have posited a connection between cerebral folate deficiency and autism.
Recent studies on the effectiveness of leucovorin for autism treatment have produced mixed results. A comprehensive review published in 2021 analyzed data from 21 studies examining the use of leucovorin for autism and cerebral folate deficiency. While the findings suggested that children receiving leucovorin experienced improved symptoms, the authors emphasized the need for further research to validate these outcomes.
A more recent study conducted in 2024 involved approximately 80 children aged two to ten with autism. Participants were divided into two groups, with one group receiving a daily maximum dose of 50 mg of folinic acid—similar in function to leucovorin—while the other group received a placebo. The results indicated that children administered folinic acid exhibited more significant improvements compared to those on the placebo.
A follow-up study in 2025 focusing on Chinese children with autism yielded similar results, with participants receiving folinic acid showing notable enhancements in social skills, particularly in social reciprocity, compared to the placebo group. Despite these encouraging findings, experts caution that more extensive and rigorous trials are necessary before any substantial changes to medical practices can be made.
Like any medication, leucovorin is not without side effects. Reported adverse reactions can include severe allergic responses, seizures, and gastrointestinal disturbances.
In conclusion, while the recent health recommendations from the US government advocate for the use of leucovorin in treating autism symptoms, the current evidence does not sufficiently support such a shift in practice. The US Food and Drug Administration has permitted physicians to prescribe leucovorin for autism treatment; however, experts urge caution. Until clinical trial data is more robust, treatment approaches for individuals with autism should continue to adhere to established evidence-based practices.
Nial Wheate, who has received funding from various health organizations, emphasizes the need for rigorous research in this area. Meanwhile, Jasmine Lee, with no conflicts of interest, supports continued investment in scientifically validated autism treatments.
