SickKids statement on White House Autism claims

On September 22, 2025, the U.S. government made several claims regarding Autism Spectrum Disorder (ASD), including a suggested link between acetaminophen use during pregnancy and Autism, the separation of vaccine doses, and the use of leucovorin to treat symptoms of Autism. These statements were made without presenting new scientific evidence and have caused confusion and concern among families, health-care providers and researchers.

At The Hospital for Sick Children (SickKids) Research Institute, our researchers are committed to advancing evidence-based understanding of Autism, a complex group of neurodevelopmental conditions that can affect a person’s communication, social skills and behaviours.

Dr. Stephen Scherer, Chief of Research and Senior Scientist, Dr. Jacob Vorstman, Psychiatrist and Senior Scientist, and Dr. Louise Gallagher, Chief, Child & Youth Mental Health Collaborative at SickKids, provide the following commentary:

On the causes of Autism

“There is no single cause of Autism. Autism arises from a complex interplay of genetic and environmental factors. In our study of nearly 4,000 families, about 20 per cent of cases could be attributed to specific genetic changes. These findings are helping us understand how different genes interact in brain development and why Autism presents so differently across individuals. Science must guide our understanding of Autism, not myths or misinformation.”

On rates of Autism

“In Canada, approximately one in 50 Canadian children and youth are diagnosed with Autism. While rates appear to be increasing, this is most likely due to increased awareness and broader diagnostic criteria. There are now about 100 genes with a scientifically validated link to Autism, each contributing only a small portion to the overall condition, and these have been endorsed for genetic testing in most of the world for the medical workup of Autistic children and children with other neurodevelopmental conditions. Factors like more common screening at doctor visits, improved availability of Autism-related services and a shift in diagnoses from intellectual disability to Autism also contribute to this rate.”

On acetaminophen and Autism

“Acetaminophen remains one of the safest options for treating fever and pain during pregnancy. The evidence linking it to Autism is weak and inconsistent. Untreated fever or pain can pose real risks to both mother and their baby. Families should consult their health-care providers and rely on trusted medical guidance.”

On leucovorin as a treatment

“Leucovorin may show promise in a small subset of Autistic children who have low levels of cerebral folate, but it is not a proven treatment for Autism symptoms. Large, well-controlled clinical trials are needed before any broad recommendations can be made.”

On vaccines and Autism

“There is no reproducible link between vaccines and Autism. Vaccines save lives and protect against serious illnesses. Families should continue to follow recommended vaccination schedules.”

On dignity and autonomy

“As we respond to these claims, it’s essential to remember that Autism is not a flaw to be fixed, but a form of human diversity to be understood and respected. Every person deserves dignity, autonomy and access to care that reflects their unique strengths, needs and preferences. Autism is a spectrum and its characteristics can vary from person to person. Our research is driven not only by science, but by a deep commitment to helping families uncover genetic diagnoses that can clarify their child’s neurodevelopmental profile and support tailored interventions.”

A call to action

Canadian researchers have long been global leaders in Autism science. We invite continued investment in science to uncover the remaining genetic and environmental factors contributing to Autism and to develop targeted support for individuals and their families. Families with questions about diagnosis or treatment should speak with their health-care providers.

To learn more, visit the AboutKidsHealth Autism Spectrum Disorder Learning Hub to explore evidence-based information and resources.

Learn more about the immunizations available to protect your child with help from the SickKids Immunization InfoLine. This free service offers live, non-judgmental, one-on-one conversations with a trained paediatric nurse to talk about any questions or concerns specific to your child or about immunizations in general.