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Pediatrician Kristin Sohl has lost count of how many times parents of children with autism have asked her for a prescription for leucovorin — the drug thrust into the spotlight after President Donald Trump touted it at a White House event this fall.

Since September, despite the rising queries, Sohl has typically told her patients no.

Early clinical trials of the drug showed hints of promise in boosting communication and cognition for some children with autism. But the studies have been small, often just a few dozen participants. Normally, approval by the Food and Drug Administration comes only after years of large-scale testing. But Trump’s pledge to fast-track the drug in September, bypassing that process, has left many doctors on the front lines divided.

“It leaves me as a practicing physician with a lot of unanswered questions,” said Sohl, a professor of pediatrics at the University of Missouri School of Medicine, who has been working in the field of autism for over 20 years.

As interest in the drug surges, Facebook groups devoted to it are swelling in membership, message boards are inundated with questions, and Google searches are climbing. Physicians, who typically rely on evidence-based guidelines and clear treatment algorithms, are finding that with leucovorin they must — lacking robust scientific data — improvise. Some are cautiously moving forward with prescribing the drug, but many are still holding off.

At Children’s National Hospital in Washington, D.C., neurodevelopmental pediatrician Sinan Turnacioglu said the hospital convened a meeting of various departments — including those specializing in autism, developmental pediatrics, genetics and psychiatry, as well as primary care doctors — to come up with a systemwide policy. Their conclusion: that they would like to see more robust research before prescribing it.

Peter Crino, chair of neurology at the University of Maryland School of Medicine and who runs a clinic for neurodivergent adults, likewise said he believes the medication is not ready for prime time.

“People are asking me a lot about it, but I do not prescribe it. Gosh I hope there will be something to the drug and it will help people in the future, but the data is simply not there yet,” he said.

Limited evidence

Each conversation Sohl has with families unfolds differently, she said, shaped by a child’s history, a parent’s worry, a flicker of hope. But the script she follows is steady: she lays out what research has shown — and what it doesn’t — about the treatment, then asks what the family hopes the drug might change.

In a field with no cure and few therapies, she uses that same framework to guide discussions about the other latest supposed breakthroughs drifting across social media — broccoli extracts, CBD oil, stem cell therapy, and more. The goal isn’t to dismiss any ideas outright but to ground them in evidence, or show the lack of it, before families decide what to do next.

For leucovorin, Sohl’s main message is that “we’re not on solid science yet.” However, there are “potential suggestions of benefit.”

Leucovorin or folinic acid has a long history of use in the context of cancer for about 50 years. It’s been shown to protect healthy cells from the toxic effects of one particular chemotherapy drug and to enhance the effectiveness of another one. Side effects were very minimal but in cancer patients have included nausea and fatigue.

For some children with autism, the immune system may produce antibodies that block the body’s ability to move folate — a vitamin essential for cell growth and DNA production — into the brain. Leucovorin, a prescription form of folate, offers a potential workaround. It crosses the blood-brain barrier by a different route, delivering the nutrient where it’s needed.

The U.S. clinical trial that got Trump’s attention is being conducted by Richard E. Frye, a pediatric neurologist who was formerly an associate professor at Arizona Children’s Hospital in Phoenix. Its design was considered the gold standard — a randomized, double-blind placebo-controlled trial — but it only had 48 children, ages 5 to 12, in it. In the trial — published in 2018 in the journal Molecular Psychiatry — the drug was well-tolerated and the parents and doctors reported improvements in communication and behavior.

Frye said in an interview that leucovorin did not work on all of his patients. But it did work for many and that children with no verbal utterances began showing meaningful word approximations, for example, and that those with phrase speech began forming full sentences.

There have been four subsequent trials in other countries, and all four of them also reported significant improvements and no serious harm. But they were also very small. A study in France with 19 patients was published in 2020, in Iran with 55 patients in 2021, in India with 40 patients in 2024, and in China with 80 patients in 2025.

The Trump administration latched onto promising research and promoted efforts to expand access to leucovorin for autism, despite the lack of large-scale clinical trials.

But since then, doctors have been proceeding cautiously. At least two influential medical societies have come out with their own interim recommendations. The American Academy of Pediatrics and the Society for Developmental & Behavioral Pediatrics both do not recommend the routine use of leucovorin for children with autism. But the AAP left an opening for doctors to prescribe it, stating that pediatric care providers “are encouraged to engage in shared decision-making with families who inquire about or request leucovorin, providing clear information about current evidence and potential risks.”

Crino said that many medical research papers — including those on leucovorin — are written in ways families can understand, and he encourages patients and their families to read the primary studies themselves. He often reviews the papers with them, he added, pointing out the limitations of the research. In the 2024 study, which was published in the European Journal of Pediatrics, for example, the authors reported that many children showed improvements in speech, but none went from nonspeaking to speaking, and the study offered no evidence about whether those changes affected daily life.

“There is a lot going on in scientific research that is getting twisted,” he said.

Turnacioglu said that some of his patients receive leucovorin from other providers. In those cases, he focuses on monitoring their progress by first establishing a baseline assessment of language and adaptive skills and then repeating the same evaluations periodically to track any changes.

In those cases, he focuses on monitoring their progress by first establishing a baseline assessment of language and adaptive skills and then repeating these evaluations periodically to track any changes.

He said the growing interest in leucovorin reflects a broader shift toward more personalized autism treatments, fueled by recent research that supports what clinicians have long observed: autism is not a uniform condition that exists along one continuous spectrum, but rather a collection of distinct conditions that have been grouped under a single label. As a result, different people may require different treatments.

“We don’t yet have enough information to use those findings to guide leucovorin treatment,” Turnacioglu said. “But it’s the kind of direction I’m excited about — figuring out which patients are going to respond to particular treatments.”

An exception

Sohl is part of a team of pediatricians who helped draft the AAP guidelines.

The patients that have approached her are all ages and across the spectrum, including adults and individuals with strong verbal skills. For months, she’d explained her reasons for holding back on leucovorin, and most families accepted them.

Then, in October, a patient sat across from her and she began to wonder if this might be an exception.

He was a teen boy she describes as minimally speaking, whom Sohl had been treating for 10 years. She was impressed by his knowledge of the research on leucovorin, his deep and realistic understanding of the potential risks and benefits, and his eagerness to document any changes both quantitatively and in narrative form. Sohl will be meeting with her patient each month to go over any changes.

“I have low expectations, his mom has low expectations, he has low expectations. But we all agreed it was worth a therapeutic trial,” Sohl said.

With the recent national attention, information about leucovorin has been spreading online far faster than through the slow, methodical channels of medical research, where studies and peer-reviewed papers can take years to emerge. She learns from the parents and patients who are often the first to encounter new ideas circulating in their communities and online.

Sohl tells families that while the drug has shown very little in the realm of side effects, this is in the context of adults with cancer, not children with autism. She said she emphasizes that she does not think this is a dangerous medicine, but there has not been enough research.

“I think it’s my duty as a doctor to say that I don’t know,” Sohl said, “and I want you to know I don’t know.”

At first, the mental health-related videos that popped up on Amy Russell’s TikTok feed made her feel seen. The tips and funny anecdotes about living with ADHD reminded her of herself — maybe her forgetfulness wasn’t a flaw but a symptom.

After two years of learning about the condition on TikTok, she went to a doctor for an assessment. The resulting diagnosis changed her life for the better, she said, as she started taking medication and using strategies to manage daily tasks. She attributes the transformation in part to TikTok.

There’s just one problem: Now she can’t get the ADHD videos off her feed. The more she scrolls, the stranger and less trustworthy the content becomes, she said. Her efforts to see less of it — scrolling past videos and not engaging — don’t seem to help.

“You just keep finding more tunnels and it gets harder to find your way out,” Russell, 35, said.

She’s not imagining it. TikTok’s algorithm favors mental health content over many other topics, including politics, cats, and Taylor Swift, according to a Washington Post analysis of nearly 900 U.S. TikTok users who shared their viewing histories. The analysis found that mental health content is “stickier” than many other videos: It’s easier to spawn more of it after watching with a video, and harder to get it out of your feed afterward.

“It felt like a rabbit hole to me because you kept going down deeper and deeper,” Russell said.

TikTok uses an algorithm to select a video and gives users two main options: Watch it or skip past to something else. Along the way, the app learns what a user like Russell likes and dislikes, based on her watching and skipping behavior. It takes skipping past 1.3 videos, on average, to undo the effect of watching one full video about cats or politics, The Post analysis found. For mental health, it takes 2.2 skips — meaning users must work harder to get it out of their feeds.

TikTok spokesperson Mahsau Cullinane criticized The Post’s methodology as incomplete and said it doesn’t “reflect the reality of how our recommendation system works.”

This finding comes amid a broader debate on the role of algorithms and influencers in Americans’ understanding of mental health. Content about mental illness and neurological differences is extremely popular across social media apps, with about as many TikTok posts using the hashtag #mentalhealth as those that mention #sports, according to data from analytics firm Sprout Social. Mental health content on TikTok deals with not just conditions like depression or anxiety, but also living with a neurological type such as ADHD or autism.

People are turning to social media for health information as Americans face a shortage of mental health professionals, barriers to accessing and paying for care, and lingering stigma. Information from social media helps underserved and underdiagnosed populations better understand themselves, many users say. What happens next, however, is rarely examined.

Over the period that The Post examined Russell’s TikTok data, about one in 11 videos on her feed were mental-health-related. Russell, who spent more than an hour watching videos on many days, said the more she scrolled, the more often she saw videos from nonprofessionals that seemed designed to get a reaction rather than educate.

Efforts to evaluate mental health content on TikTok support Russell’s impression. Anthony Yeung, a psychiatrist and University of British Columbia researcher, ran a study examining 100 top TikTok videos about ADHD and found that some were helpful, but about half were misleading. (Videos about creators’ personal experiences weren’t classified as misleading.) Other reviews of TikTok content about ADHD and autism by mental health practitioners have found similar results.

“The algorithm says, ‘Well, you like this video about ADHD, even though it’s misleading, let’s give you another video,’” Yeung said. “And it becomes this very vicious feedback loop of misinformation.”

The phenomenon is having a profound effect on real-world mental health treatment, clinicians say. Yeung said he deals with “two visions of what ADHD is”: the one discussed on social media and the one he sees among actual patients. On TikTok, ADHD content often paints with a broad brush, portraying common quirks or struggles as not just personal experiences but diagnostic criteria for the condition.

One popular ADHD account, @lifeactuator, regularly earns views in the millions with titles like “What ADHD feels like” and “Things people with ADHD do despite knowing better.” One widely watched video with the caption “if the world was made for ADHD” depicts a Costco store with ADHD shoppers being chased around by store employees to stop them from making impulse purchases.

Eric Whittington, the Arizona-based creator behind @lifeactuator, said that because of the constraints of short-form video, he’s not able to include all the information viewers might need to understand what, if anything, his videos reflect about ADHD as an actual medical condition. Taken individually, his videos probably apply to a broad swath of the population, he said — not just people with ADHD.

“When you only have a minute to work with, it’s hard to add disclaimers on the content saying, ‘Yes, everybody experiences this from time to time, but if it happens all the time, you may have ADHD,’ ” he said.

Rana Coniglio, an Arizona-based therapist who works primarily with Gen Z clients, said they often arrive at her practice already attached to a diagnosis they found on TikTok. Sometimes, that attachment makes it harder to accurately diagnose or make a treatment plan that could improve that person’s symptoms.

“I have had people come to me and say, ‘Hey, I saw this video on TikTok and it’s actually the reason that I’m seeking therapy because it made me think I actually do need help,’ and there are benefits to that,” she said. “But I think the majority of people see a diagnosis, take it and run with it.”

High volume, low quality

For Ace Bannon, a 19-year-old in Utah, the more he watched, the darker the content became.

Bannon first got curious about autism and its characteristics after learning that many of his best friends — people he’d met on a Discord server — were autistic. He started watching TikTok videos, with content about autism taking up a growing chunk of his feed. Then, TikTok served him video after video of autistic adults discussing the trauma they endured as children, Bannon said. Before long, he wanted his old algorithm back.

“Because you’re interested, it starts recommending more of those videos and it makes you fall into these rabbit holes that you just want to get out of after a while, but you can’t.”

Sometimes this experience actually exacerbates existing mental health problems, some users say. Kailey Stephen-Lane, 30, said she had to temporarily stop using the app because spending time on TikTok was worsening the symptoms of her obsessive compulsive disorder. While her real-life therapist was helping her sit with fears and insecurities without fixating, TikTok was “bombarding” her with videos about the very symptoms that made her so anxious, she said.

“The TikToks that I’ve been getting are not helpful to my recovery,” she said. “They lead me down a lot of spirals, and me just clicking ‘not interested’ doesn’t seem to work anymore.“

TikTok provides a high-level description of some of the data its algorithm uses but few details. That makes it difficult to know why mental health videos are stickier than other topics, says Stevie Chancellor, an engineering professor at the University of Minnesota who studies AI and its risks, and whose research found that the algorithm creates a “runaway train” of mental health content.

But the app’s business incentives offer some clues, Chancellor says. Maybe users who see a lot of mental health videos spend longer on the platform or are more likely to spend money down the line, she said. Maybe the effect is completely unintentional, an example of a black-box algorithm optimizing for what it thinks users want.

“Watching [mental health] content might lead to other behaviors that are valuable on the platform,” Chancellor said.

The topic may become sticky because it’s one “that a user only wants to engage with sometimes,” said Laura Edelson, a computer science professor at Northeastern University who collaborated with The Post in a parallel TikTok research effort.

Cullinane, the TikTok spokesperson, said the company is “transparent” about how its feed works.

For TikTok users, adjusting the type of content that shows up on their feeds can be hard. It’s not always clear when engaging with a certain video would spawn something undesirable: Even watching clips about romantic relationships made a user more likely to encounter mental health content, The Post’s analysis found. TikTok has gradually added options that could help users tailor their feeds, such as clicking a “not interested” button, blocking videos with certain keywords or resetting their algorithms from scratch. A new “Manage Topics” menu lets users adjust the prevalence of 12 specific topics on their For You page — but mental health isn’t one of them.

As for Russell, she is glad for the journey toward an ADHD diagnosis because of TikTok. She just wishes her favorite type of content — lighthearted cat videos — got the same treatment from the app’s algorithm.

“I want like 10-20% cute cat videos, probably even like 30%,” she said. “But those disappear really quickly.”

Methodology

Hundreds of TikTok users in the United States sent their watch history data to The Washington Post. We downloaded the collective 14.8 million videos they’d been shown and then sorted them into topics, based on keywords in the transcripts and on-screen text. The Post calculated the stickiness of each topic by computing the difference between the number of topical mental health videos each user had been shown in the previous 50 videos and how many they saw in the next 50. We averaged this for all videos, aggregated by whether the user watched at least 90% of the video, or skipped it.