• Posted March 11, 2026

FDA Approves Drug for Rare Brain Disorder, Not Autism

The U.S. Food and Drug Administration (FDA) has approved a generic drug for a very rare brain disorder, but said it should not be considered a treatment for autism.

On Tuesday, the agency cleared leucovorin for people with a genetic condition that prevents enough folate, a form of vitamin B, from reaching the brain. 

The FDA estimates the disorder affects fewer than 1 in a million people in the United States.

The decision follows months of ambiguity after officials said the drug might help people with autism.

In September, President Donald Trump and FDA Commissioner Dr. Marty Makary said the medication was being reviewed as a possible treatment for autism.

“It might be 20, 40, 50% of kids with autism,” Makary said at the time.

But FDA officials said Monday that the agency later focused only on the strongest scientific evidence. That evidence only supported the drug’s use for people with the rare genetic mutation affecting folate in the brain.

Officials also noted that one study supporting the drug’s use for autism was retracted earlier this year.

Autism researchers say the drug has not been proven to help most people with the condition.

“There is no evidence to say that leucovorin will help most people with autism, and there’s certainly no evidence to say it’s safe,” Dr. Alycia Halladay of the Autism Science Foundation, told The Associated Press in an interview.

Leucovorin is a lab-made form of folate that doctors have used for years to reduce side effects from certain chemotherapy medications and to treat a rare blood disorder.

People with the condition targeted by Tuesday’s approval may develop movement problems, seizures and other neurological symptoms that can sometimes resemble autism.

But major medical groups are cautious about using leucovorin for autism.

The American Academy of Pediatrics does not recommend its use for children with autism, including those with a condition called cerebral folate deficiency.

But despite the uncertainty, prescriptions for leucovorin have increased.

A recent study in The Lancet found that prescriptions for children ages 5 to 17 rose 71% in the three months following the White House announcement last September.

“We’ve seen huge increases in leucovorin prescriptions for autism because of the initial premature and ill-informed announcement that it can treat autism symptoms,” David Mandell, an autism expert at the University of Pennsylvania, told The AP.

"Now families are experiencing whiplash about what constitutes best practice for their children," Mandell added.

Some families have also reported difficulty filling prescriptions recently due to supply shortages.

FDA officials said the agency is allowing foreign manufacturers to help with supply. The drug’s original maker, GSK, does not plan to relaunch its version.

Halladay warned that parents should be careful about trying the drug for autism.

Reports have linked the medication to side effects such as irritability, aggression and hyperactivity in some patients.

“If parents are insistent on trying this they should know that it may cause harm and it may do no good,” Halladay said.

Researchers say autism likely results from a mix of genetic and environmental factors, and there is still no single known cause.

More information

The National Organization for Rare Disorders has more on cerebral folate deficiency.

SOURCE: The Associated Press, March 10, 2026