After spending much of his childhood barely able to mutter more than a few words at a time, the young boy suddenly began speaking in full sentences at age 8. And his first order of business? Setting the record straight.
“He had a laundry list of everything that had upset him over the years,” his mother, Dr. Kathleen Schnier, told The Post with a laugh.
Nathaniel Schnier, a 13-year-old with autism, has shown remarkable progress thanks to leucovorin.
From disappointing dinners and denied desserts to long-held grudges against his older sister, it was clear Nathaniel had been waiting years to be heard.
“He was retaining absolutely everything,” said his mother, Kathleen Schnier, 54. “People weren’t including him in conversations or assumed he didn’t understand, but it was all there.”
Now 13, Nathaniel is among a growing number of young people with autism finding their voice with the help of leucovorin—a cheap, generic drug opening new channels of communication, one long-overdue complaint at a time.
A voice gone quiet
The second child of Kathleen and Paul Schnier, Nathaniel was a babbling, social toddler who made eye contact easily and eagerly engaged with the world around him.
But as he grew, he began to fall behind, missing developmental milestones.
“He didn’t start walking until 14 months, and then he began regressing with his words,” said Kathleen, provost and chief academic officer at Colorado Tech University. “That was when I realized something was off.”
Initially, doctors dismissed her concerns, suggesting she was simply comparing Nathaniel to his older sister, who had walked and talked early.
The Schnier family lives in Phoenix, Arizona.
But Kathleen—ever the determined “mama bear”—pushed for answers. She enrolled Nathaniel in early intervention services at just 17 months, including speech, developmental, and occupational therapy.
By age 2, Nathaniel could only repeat what others said or use a single word to express basic needs, like “water” or “outside.”
At 3, he was diagnosed with autism, receptive-expressive language disorder, and ADHD.
“You could never have a conversation with him,” Kathleen said. “That was the most horrendous thing as a parent: knowing you can’t have a conversation with your own child, or that someone could hurt him and he couldn’t tell you.”
A new frontier in treatment
After his diagnosis, Nathaniel continued multiple therapies, but Kathleen kept searching for additional options.
In 2021, she discovered a notice in the Federal Register recruiting participants for a double-blind clinical trial led by Dr. Richard Frye.
“It was like something clicked. He went from one or two words to full-on sentences within six months.”
Kathleen Schnier
The pediatric neurologist was studying whether leucovorin could help autistic children with cerebral folate deficiency—a shortage of vitamin B9 in the brain.
Research suggests that up to 70% of autistic children have antibodies that block folate transport into the brain, contributing to speech delays and behavioral challenges.
Leucovorin has been used safely for decades.
Frye theorized that leucovorin, a form of folate, could bypass the antibody block and more effectively deliver the nutrient to the brain, potentially easing symptoms. The drug was first approved in 1988 to reduce the toxic effects of chemotherapy.
In an early study of 44 children, Frye found that 67% of those taking a twice-daily leucovorin pill showed improvements in both receptive and expressive language within 12 weeks—with no serious adverse effects.
“If you’re going to the doctor looking for an autism pill, it doesn’t exist,” Frye, now director of research at the Rossignol Medical Center in Phoenix, previously told The Post. “But leucovorin has helped a lot of children.”
The drug costs about $100 per month without insurance—and as little as $10 with coverage.
Finding Nathaniel’s voice
Kathleen was intrigued—and amazed—to discover that Frye’s latest study was taking place at Phoenix Children’s Hospital, just a mile and a half from their home.
After testing confirmed that Nathaniel had both the antibody and a cerebral folate deficiency, he was enrolled in the trial. It became clear almost immediately that he hadn’t been given a placebo.
“When he started taking leucovorin, it was like something clicked,” Kathleen said. “He went from one or two words to full-on sentences within six months.”
Thanks to leucovorin combined with ongoing therapies, Nathaniel can now speak after spending most of his childhood nonverbal.
With his newfound voice, Nathaniel finally found a way to express what had been locked inside for years.
“The TV in my brain, I can say it in my mouth,” Kathleen recalled him telling her. “It was always there; he just couldn’t say it.”
But she is careful to note that the medication wasn’t a cure-all. Nathaniel had been enrolled in speech, developmental, and occupational therapies since he was 17 months old—interventions that laid the crucial foundation for his progress.
“I don’t want people to be like, ‘Oh, we’re going to cut services for disabled children, but here’s a pill.”
Kathleen Schnier
“Suddenly, he had the capability of talking, but he had to learn how,” Kathleen said.
“When you have a conversation with a person, you have to ask them things and listen to them. It’s not all about what you want to say the whole time, and he can do that now—but leucovorin didn’t do that for him,” she explained. “Speech therapy did that for him.”
Many of Frye’s patients continue their therapeutic interventions while taking the drug.
“You have to treat a lot of things to make the body well,” Frye said. “What [leucovorin] does, we think, is accelerate the effectiveness of all these therapies.”
Speaking freely, living fully
Today, Nathaniel takes guitar and trumpet lessons. He’s a member of the Phoenix Children’s Chorus and recently sang the national anthem at a Diamondbacks game.
The 13-year-old is also active in Special Olympics golf, swims on a local team, and is working toward scuba diving certification. Last month, he even flew solo to New York City to visit his sister.
“I want to be an ice cream man,” Nathaniel told The Post as he dashed out the door for school, dreaming big about his future.
Nathaniel experiences no side effects from leucovorin, aside from brief irritability that faded within weeks of starting the medication.
As the Trump administration moves to expand access to leucovorin for families like the Schniers, Kathleen supports the effort—but with a major caveat.
“This is not a magic pill. You still have to put in the hard work, and it might not work,” she said, noting that several participants in Nathaniel’s trial didn’t see improvements with leucovorin.
“It definitely works in Nathaniel’s favor to be taking this medication, but I don’t think it’s a wonderful drug for everyone,” Kathleen added.
She also worries that too much focus on the drug could lead to cuts in critical services that many children rely on.
Just this month, Arizona began slashing $47 million in services for up to 18,000 disabled children due to budget shortfalls—a move local advocates warn will cause “catastrophic damages” to families.
“I don’t want people to think, ‘Oh, we’re going to cut services for disabled children, but here’s a pill,’” Kathleen said.
“If you’re going to support the disabled community, you have to provide comprehensive resources—and then you’ll see the amazing results you see with Nathaniel.”
