Autism Causes
We know that families want clear answers about what causes autism, and we understand how overwhelming it can feel when new reports raise more questions. While research continues to teach us more, there is currently no single known cause of autism. Evidence suggests that autism likely develops from a combination of genetic, biological, and environmental factors—rather than any one thing alone.
Recently, some media reports have suggested that taking acetaminophen during pregnancy, or giving it to children, might be linked to autism. We know how unsettling it can be to hear this, especially since acetaminophen is so commonly used. We want you to know that leading medical organizations, including the American Academy of Pediatrics (AAP), agree that the current scientific evidence does not support a link between acetaminophen and autism.
Acetaminophen has been studied for decades and, when used as directed, is considered both safe and effective for children. However, infants younger than 12 weeks should only receive it under the guidance of their pediatrician.
If you’re pregnant and have questions about using acetaminophen, it’s always best to talk with your obstetrician. These resources from the American College of Obstetricians and Gynecologists (ACOG) may also be helpful:
- ACOG Affirms Safety and Benefits of Acetaminophen during Pregnancy
- Acetaminophen in Pregnancy: Frequently Asked Questions
About Leucovorin
We also understand that recent headlines about the drug leucovorin have caused confusion and raised hopes. We want to help clarify what’s currently known.
The FDA is in the process of approving leucovorin for patients with cerebral folate deficiency (CFD)—a condition that can share some symptoms with autism, such as developmental delays, sensory challenges, and repetitive behaviors. However, CFD is a rare, distinct disorder that can also cause seizures and tremors. Diagnosis requires a lumbar puncture to examine the cerebrospinal fluid.
The FDA’s decision is based on small studies showing that leucovorin may improve communication skills in children with CFD. While it’s natural to hope that similar benefits might extend to children with autism, leucovorin is not currently approved for treating autism. Specialists in autism care and organizations such as Autism Speaks agree that more large-scale, carefully controlled studies are needed to confirm safety, determine appropriate dosages, and understand potential side effects before it can be responsibly prescribed to a wider population.
We share your hope for new therapies that could improve the lives of children with autism and their families. We will continue to follow this research closely and keep you updated as more evidence becomes available.
Helpful resources:
Published on: 10/3/2025