Nadine Burke at her San Francisco clinic. Photograph by Alessandra Sanguinetti / MAGNUM PHOTOS

Monisha Sullivan first visited the Bayview Child Health Center a few days before Christmas, in 2008. Sixteen years old, she was an African-American teen-age mother who had grown up in the poorest and most violent neighborhood in San Francisco, Bayview-Hunters Point, a bleak collage of warehouses and one-story public-housing projects in the city’s southeastern corner. Sullivan arrived at the clinic with ailments that the staff routinely observed in patients: strep throat, asthma, scabies, and a weight problem. The clinic’s medical director, Nadine Burke, examined Sullivan and prescribed the usual remedies—penicillin for her strep throat, ProAir for her asthma, and permethrin for her scabies—and at most clinics that would have been the end of the visit. But Burke, who founded the center in 2007, was having a crisis of confidence regarding her practice, and Sullivan was the kind of patient who made her feel particularly uneasy. Burke was diligently ticking off each box on the inner-city pediatrician’s checklist, but Sullivan’s problems appeared to transcend mere physical symptoms. She was depressed and listless, staring at the floor of the examination room and responding to Burke’s questions in sullen monosyllables. She hated school, didn’t like her foster mother, and seemed not to care one way or the other about her two-month-old daughter, Sarai.

Burke is charismatic and friendly, and her palpable concern for her patients disarms even the toughest cases. It helps that she is dark-skinned, like most of her patients, and young—just thirty-five. But her childhood was very different from theirs. The daughter of Jamaican professionals who moved from Kingston to Silicon Valley when Burke was four, she attended public school in Palo Alto, where the kids were mostly white and well-off, and where girls cried in the cafeteria if they didn’t get the right car for their sixteenth birthday. Like many children of immigrants, Burke has learned to move fluidly between cultures. She now lives in a house in an upscale part of Potrero Hill, a San Francisco neighborhood, with a closet full of designer clothes, and she has a fiancé who is a wealthy solar-energy entrepreneur. But she seems just as comfortable among the mostly poor families she sees in her examination room: laughing, gossiping, hugging, and scolding, in Spanish as well as in English, in a full-throated alto that echoes down the hall.

At the clinic, Burke gently interrogated Sullivan until she opened up about her childhood: her mother was a cocaine addict who had abandoned her in the hospital only a few days after she was born, prematurely, weighing just three and a half pounds. As a child, Sullivan lived with her father and her older brother in a section of Hunters Point that is notorious for its gang violence; her father, too, began taking drugs, and at the age of ten she and her brother were removed from their home, separated, and placed in foster care. Since then, she had been in nine placements, staying with a family or in a group home until, inevitably, fights erupted over food or homework or TV and Sullivan ran away—or her caregivers gave up. She longed to be with her father, despite his shortcomings, but there was always some reason that he couldn’t take her back. For a long time, she had the same dream at night: taking the No. 44 bus back to Hunters Point, walking into her father’s house, and returning to her old bedroom, everything just as it used to be. Then she’d wake up and realize that none of it was true.

When I met Sullivan, last September, she had recently turned eighteen, and three days earlier she had been emancipated from foster care. She was now living alone, in a subsidized apartment off Fillmore Street. In California, emancipated foster children are given a summary of their case file, which meant that Sullivan had just been handed an official history of her rootless adolescence. “It brought up a lot of emotions,” she told me. “I read it, and I kind of wanted to cry. But I was just, like, ‘It’s over with.’ ” The most painful memory was of the day, in fifth grade, when she was pulled out of class by a social worker she had never met and driven to a strange new home. It was months before she was able to have contact with her father. “I still have dreams about it,” she told me. “I feel like I’m going to be damaged forever.”

I asked Sullivan to explain what that damage felt like. For a teen-ager, Sullivan is unusually articulate about her emotional state—when she feels sad or depressed, she writes poems—and she evoked her symptoms with precision. She had insomnia and nightmares, she said, and at times her body inexplicably ached. Her hands sometimes shook uncontrollably. Her hair had recently started falling out, and she was wearing a pale-green head scarf to cover up a thin patch. More than anything, she felt anxious: about school, her daughter, even earthquakes. “I think about the weirdest things,” she said. “I think about the world ending. If a plane flies over me, I think they’re going to drop a bomb. I think about my dad dying. If I lose him, I don’t know what I’m going to do.” She was even anxious about her anxiety. “When I get scared, I start shaking,” she said. “My heart starts beating. I start sweating. You know how people say, ‘I was scared to death’? I get scared that that’s really going to happen to me one day.”

Sullivan encountered Nadine Burke at a moment when Burke was just beginning to think deeply about the physical effects of anxiety. She was immersing herself in the rapidly evolving sciences of stress physiology and neuroendocrinology, staying up late reading journals like Molecular Psychiatry and Nature Neuroscience. Burke had just learned of a pioneering study, conducted in San Diego, on the long-term health effects of childhood trauma, and its conclusions had led her toward a new way of thinking—not just about her clinical practice but about the entire field of pediatric medicine.

As she listened to Sullivan, Burke found herself inching toward a diagnosis that, a year earlier, would have struck her as implausible. What if Sullivan’s anxiety wasn’t merely an emotional side effect of her difficult life but the central issue affecting her health? According to the research Burke had been reading, the traumatic events that Sullivan experienced in childhood had likely caused significant and long-lasting chemical changes in both her brain and her body, and these changes could well be making her sick, and also increasing her chances of serious medical problems in adulthood. And Sullivan’s case wasn’t unusual; Burke was seeing the same patterns of trauma, stress, and symptoms every day in many of her patients.

Two years after Sullivan’s first visit, Burke has transformed her practice. Her methodology remains rooted in science, but it goes beyond the typical boundaries of medicine. Burke believes that regarding childhood trauma as a medical issue helps her to treat more effectively the symptoms of patients like Sullivan. Moreover, she believes, this approach, when applied to a large population, might help alleviate the broader dysfunction that plagues poor neighborhoods. In the view of Burke and the researchers she has been following, many of the problems that we think of as social issues—and therefore the province of economists and sociologists—might better be addressed on the molecular level, among neurons and cytokines and interleukins. If these researchers are right, it could be time to reassess the relationship between poverty, child development, and health, and the Bayview clinic may turn out to be a place where a new kind of pediatric medicine is taking its tentative first steps.