CRANSTON, R.I. — Audrey Pirri, 16, had been terrified of vomiting since she was a toddler. She worried every time she shared a meal with family or friends, restricting herself to “safe” foods like pretzels and salad that wouldn’t upset her stomach, if she ate at all. She was afraid to ride in the car with her brother, who often got carsick. She fretted for hours about an upcoming visit to a carnival or stadium — anywhere with lots of people and their germs.

But on a Tuesday evening in August, in her first intensive session of a treatment called exposure therapy, Audrey was determined to confront one of the most potent triggers of her fear: a set of rainbow polka dot sheets.

For eight years she had avoided touching the sheets, ever since the morning when she woke up with a stomach bug and vomited on them. Now, surrounded by her parents, a psychologist and a coach in her pale pink bedroom, she pulled the stiff linens from her dresser, gingerly slid them over the mattress and sat down on top.

“You ready to repeat after me?” said Abbe Garcia, the psychologist.

“I guess,” Audrey replied softly.

“‘I am going to sleep on these sheets tonight,’” Dr. Garcia began. Audrey repeated the phrase.

“‘And I might throw up,’” Dr. Garcia said.

Audrey paused for several long seconds, her feet twitching and eyes welling with tears, as she imagined herself vomiting. She inhaled deeply and hurried out the words: “And I might throw up.”

One in 11 American children has an anxiety disorder, and that figure has been growing steadily for the past two decades. The social isolation, family stress and relentless news of tragedy during the pandemic have only exacerbated the problem.

But Audrey is one of the relatively few children to have tried exposure therapy. The decades-old treatment, which is considered a gold-standard approach for tackling anxiety, phobias and obsessive-compulsive disorder, encourages patients to intentionally face the objects or situations that cause them the most distress. A type of cognitive behavioral therapy, exposure often works within months and has minimal side effects. But financial barriers and a lack of providers have kept the treatment out of reach for many.

After another minute, as Audrey sat in plain discomfort, Dr. Garcia offered her a tissue. “Being brave and sticking with it while you’re feeling that way — that’s the way it’s going to get better,” she said.

In 2013, Dr. Garcia and other clinicians at Bradley Hospital, a children’s psychiatric facility outside Providence, developed a model to bring the therapy to more patients, training “coaches” without advanced degrees to lead exposure sessions. Last year, she and a colleague, Dr. Brady Case, left the hospital to start a company, Braver, which enlists such coaches to try to meet soaring demand for anxiety treatment across the country.

Exposure therapy is fairly intuitive; each session is akin to the habituation that comes after jumping into a cold pool. Which is not to say that the treatment is easy. In a world of trigger warnings and safe spaces, many people have grown increasingly adept at avoiding emotional discomfort. But the premise of exposure therapy is that anxiety should not be indulged — and that its worst effects can be vanquished.

“I don’t want to overuse the word ‘cure,’ but that’s what we’re going for,” Dr. Case told Audrey and her parents a couple of weeks before the teen’s first exposure. “We’re not going for the end of anxiety, but we’re going for the end of anxiety creating obstacles that you can’t overcome.”

Little Albert and Little Peter

Exposure therapy grew out of behavioral principles that emerged in the late 19th century from a digestion laboratory in St. Petersburg, Russia. In experiments now taught in any introductory psychology course, Ivan Pavlov found that dogs salivated not only in the presence of food but also on hearing the approach of the person who routinely fed them. Subsequent studies showed that a dog’s drooling response could be triggered by a range of unrelated stimuli, from metronomes to electric shocks.

Some two decades later, inspired from afar by Pavlov, John B. Watson, a psychologist at Johns Hopkins University, carried out similar, disturbing experiments on an 11-month-old infant who came to be known as “Little Albert.” A typical baby, Albert cried in fear on hearing the clang of a steel rod being struck. Watson had the infant pet a white rat while hearing this sound, and succeeded in making him afraid of the rat and other objects resembling it: a rabbit, a fur coat, even a Santa Claus beard.

One Friday evening in 1919, as Watson lectured about this research in New York City, a young woman in the audience sat in rapt attention. Mary Cover Jones, a college student with a keen interest in psychology, watched Watson project a film of the frightened Little Albert. She wondered: If negative associations could induce a child’s fear, could positive ones extinguish it?

Jones went on to test the idea with “Little Peter,” who was nearly 3 and afraid of rats and rabbits. Day after day, Peter and several children without phobias entered a room at Columbia University and played with a rabbit. Over the first seven sessions, as Jones described in a 1924 paper, “Peter progressed from a great fear of the rabbit to a tranquil indifference and even a voluntary pat on the rabbit’s back when others were setting the example.”

Jones’s report, perhaps the first documented use of exposure therapy, was largely ignored. But three decades later Joseph Wolpe, a psychiatrist in South Africa, began building on the ideas to create a robust new therapy.

During World War II, Wolpe had been a medical officer for the South African army, treating traumatized soldiers with a Freudian approach called narcoanalysis: The men were given a barbiturate to help them access “repressed” memories from the battlefield. It didn’t work, and left the doctor disillusioned.

After the war, Wolpe dove into the work of Pavlov and Jones, and carried out experiments on cats that had been trained with electric shocks to fear their cages. Wolpe repeatedly fed the scared cats while in their cages, which lessened their fear response over time.

Through the 1950s, Wolpe treated many people with phobias. He developed a now-common technique, called an “anxiety hierarchy,” in which the patient began with a mild exposure that elicits little fear, then gradually worked up to more disturbing situations.

In a 1954 report of 122 patients, he found that 90 percent were either “much improved” or “apparently cured.”

Intentional Discomfort

In the decades since, dozens of clinical studies have shown the effectiveness of exposure therapy. By some estimates, 2 out of 3 children are rid of their diagnoses within four months of the treatment. And the effects can last for years.

“There’s clear evidence across trials using exposure that this is a very effective strategy that helps reduce anxiety symptoms over time,” said Dr. Carol Rockhill, a psychiatrist at Seattle Children’s Hospital. Dr. Rockhill is one of the authors of clinical guidelines from the American Academy of Child & Adolescent Psychiatry that recommend cognitive behavioral therapy and medications, alone or in combination, as treatments for children with anxiety.

“I’ve seen really amazing cases where kids are highly impaired by their anxiety, and after engaging with exposure they have really profound improvement in their life,” she said.

The upheaval of the last two years has left many young people with emotional scars, compounding a trend that began well before the pandemic. In 2021, 9.3 percent of children had been given a diagnosis of anxiety disorder, up from nine percent in 2019 and 7.1 percent in 2016, according to a large national survey conducted by the Health Resources and Services Administration.

Yet relatively few therapists — under 25 percent, some studies suggest — practice exposure therapy.

One reason is that many therapists balk at the notion of intentionally making their clients feel worse, said Jennifer Gola, a clinical psychologist at the Center for Emotional Health of Greater Philadelphia, who has researched the phenomenon. “They have a hard time bearing watching somebody in distress and think that it’s just cruel,” she said.

In 2013, clinicians at Bradley Hospital reasoned that exposure therapists need not be only clinical veterans like themselves. They trained coaches with no previous education beyond a bachelor’s degree to conduct exposures outside the hospital, where children could confront their real-world triggers.

“We all want kids to get more care,” said Jennifer Freeman, a clinical psychologist and the director of the Pediatric Anxiety Research Center at Bradley. “There’s not enough access, not enough treatments and there will never be enough of us doing this.”

Since then, more than 650 children and adolescents have worked with the center’s exposure coaches, she said. Several clinical trials are measuring the treatment’s effectiveness, she added, and data from one study is now under review at a scientific journal.

Since leaving Bradley to start Braver, Dr. Garcia and Dr. Case have treated about 90 patients in the Providence area and plan to open two sites around Boston next year.

When Sara Swanson, 24, became a coach for Braver in March, after a year working as a counselor at a recreational program for children with disabilities, she was surprised at the extent to which exposure therapists must think on their feet, constantly calibrating their patient’s level of discomfort.

“Exposure is like being very practiced in improv,” she said.

One evening this August, she sat at a kitchen island with Jason Burlingame, 10, and guided him through plates of food as he worried about choking on each bite. The next day, she took Gavin, 13, to the Warwick Mall and encouraged him to risk extreme embarrassment by riding a carousel near the front entrance. (Gavin and several other children requested to withhold their last names because of privacy concerns.)

For many of Ms. Swanson’s patients, recovery is fast. A few hours before meeting with Gavin, she had gone to Denny’s and led a session with Ella, 7, who happily devoured pancakes and bacon while her grandfather watched in near tears, recalling how little the girl was eating before starting therapy two months earlier.

For others, though, progress is slower. Maeve, a 12-year-old from Seekonk, Mass., has struggled since age 3 with a fear of dying, being physically harmed or getting sick. She couldn’t be separated from her mother and avoided food, leading to drastic weight loss. She has been in exposure therapy, first at Bradley and now with Braver, since age 6. Although the treatment has gradually helped her regain the weight and thrive in school, some meals are still difficult.

Maeve described anxiety as a “worry monster” that would always live in her mind. “It won’t ever be able to disappear,” she said. “But what I learned is, you have to be like, ‘Yeah, I know you’re here, but I don’t care,’ and then it will slowly disintegrate.”

Her parents call her “Brave Maeve.”

Searching High and Low

Despite its long history and robust evidence base, exposure therapy is hard to access in the United States — especially for families who aren’t well off.

“The good therapists who do this, they often don’t take insurance, because they don’t have to,” said Monnica Williams, who runs exposure therapy clinics in Connecticut and Ottawa, and has studied the treatment’s use in different racial and ethnic groups. “And so that might make the treatment inaccessible for people who can’t afford it.”

Government statistics on mental health treatments for children reveal startling racial gaps. In 2019 (the most recent year available), 12.4 percent of white children reported getting counseling or therapy, compared with 7.6 percent of Hispanic and 6.9 percent of Black children.

Braver, using a ratio of three less-expensive coaches for every one psychologist, is trying to make the insurance reimbursement model work on a large scale. The company charges insurance about $3,500 for 16 weeks of care, which is comparable to other programs.

For now, just one medical insurer, Blue Cross and Blue Shield of Rhode Island, has agreed to cover the care provided by Braver’s bachelor’s-level coaches. In September, the insurer finalized an agreement to cover Bradley’s exposure coaches as well.

“This use of nonclinical coaches is really smart,” said Martha Wofford, the insurer’s president and chief executive. The model was appealing, she said, in part because it allows more children to get care early, before their problems spiral into situations requiring emergency visits or stints in inpatient wards.

Manny Padilla, 17, struggled with O.C.D. for a decade before it advanced to a crisis that finally gave him access to treatment.

His many fears had left him confined to his house in Cranston since the fourth grade. He often spent several hours in the shower, stuck in mental loops, picking up and putting down shampoo bottles. After watching a science-fiction television show, he became particularly fearful of electricity, convinced that one wrong touch of a light switch could zap him into another dimension.

His mother, Lori Padilla, searched for treatment programs that would accept his government insurance, Medicaid, but all had long waiting lists, and she couldn’t afford private-pay programs. Manny grew terrified whenever she left the house, making it difficult for her to keep a job. “My only salvation was going to be through a program that I couldn’t afford to pay for,” she said.

In February, Manny’s brother found him in the kitchen in the middle of the night, holding a knife and about to hurt himself. The severity of his illness caused him to be admitted to Bradley’s exposure program.

After eight months of therapy, first in the hospital and then as an outpatient, Manny can now be by himself for long periods, and his showers end after 10 or 15 minutes. He still struggles with pacing and obtrusive thoughts, but he believes he will be able to one day live independently.

Across town, Audrey Pirri has also been impressed with the treatment’s affect on her vomiting fears. She knows now that her phobia probably won’t go away. But it no longer runs her life.

One evening in September, she came home from marching band practice and signed into Google Meet for a virtual session. Her therapist and coach guided her to kneel in front of a toilet, grab the seat as if she were going to vomit and share her thoughts.

“What if I get sick?” she said.

After five minutes of intense stress, Audrey’s anxiety began to fade. By minute nine, she was bored. “I’m kind of just like, why am I sitting here?” she said, giggling.