Why More and More Girls Are Hitting Puberty Early

“Leptin is not so much the trigger for puberty as it’s permissive,” Paul Kaplowitz, a professor emeritus of pediatrics in the division of endocrinology at Children’s National Hospital in Washington, D.C., told me. “An adequate level of fat tissue is a requirement for puberty to progress. But we don’t know for sure if fat is the only reason why girls in the twenty-first century are maturing earlier than girls in the latter part of the twentieth century. Obesity is a big part of the story. It’s not the whole story.”

Given everything we understand about the mechanisms of puberty, it feels intuitive and logical that some percentage of lockdown kids, who might have otherwise followed a more Tanner-like progression in their physical development, may have tipped into early puberty thanks to a conspiracy of increased calorie intake, more fatty and processed foods, and decreased exercise, as well as the manifold sources of stress and anxiety that the pandemic generated during a pivotal stage of their development. Like early puberty itself, mental-health problems among children and teen-agers were on the rise before the pandemic, and skyrocketed during and after it. Between 2009 and 2019, according to data from the U.S. Surgeon General’s office, rates of depression and suicidal ideation among high-school students all rose significantly. Approximately one in three kids in this age group reported “persistent feelings of sadness or hopelessness”; in a C.D.C. study of high-school students conducted in 2021, this number had risen to forty-four per cent. Mental-health-related emergency-room visits for children ages five to eleven increased by twenty-four per cent from March to October, 2020, as compared with the same period in 2019; for kids ages twelve to seventeen, the figure was thirty-one per cent. Child psychologists are overwhelmed with new-patient requests, and many have stopped taking insurance. The National Association of School Psychologists has stated that there is roughly one school psychologist for every twelve hundred students in the U.S.

A crucial, perhaps overlooked link between early puberty and the youth mental-health crisis is sleep. Marlon Goering, a doctoral student in psychology at the University of Alabama at Birmingham, studies the relationship between pubertal timing and behavioral challenges in young people. He told me that melatonin, the sleep-regulating hormone that the brain produces in response to darkness, may have contributed to the pandemic-era jump in early puberty. During the lockdowns, many children got less sleep and more irregular sleep, and they spent vastly more time in front of the blue light of screens, which inhibited their ability to secrete melatonin. A drop in melatonin can contribute to symptoms of anxiety and depression; it also activates an increase in a protein called kisspeptin, which is another of the trigger hormones for puberty. The melatonin-disrupting effects of blue light may have persisted long past the acute phase of the pandemic: many schools and students have continued using the iPads and Chromebooks that they acquired to facilitate remote learning, and many households never reset the screen-time rules that they had in place before lockdown obliterated them.

Some pediatric endocrinologists suspect that the recent spike in early puberty may be subtly different from the decades-long rise that preceded it. Greenspan, of Kaiser Permanente, San Francisco, and other colleagues have noticed that, among their consultations for early puberty, they are not seeing as many girls with higher B.M.I. as they did pre-pandemic. She also said that pubertal tempo—the total time it takes to progress from thelarche to menarche—is speeding up among her patients, regardless of B.M.I. If large-scale data eventually bear out Greenspan’s observations, it would likely mean that the average age of first period, which has remained relatively stable over the last eighty years, may begin to drop more noticeably, even if only for a micro-generation of kids.

Much of the time, early puberty does not require medical intervention (although, in rare cases, it may be caused by a brain tumor or by a disorder of the patient’s ability to produce cortisol). “I can’t tell you how many kids come into my practice who have their periods early, and when the parents don’t make a deal out of it, the kids tend to be fine—‘Yeah, it’s kind of annoying, but Mommy showed me how to change the pad.’ And you’re talking to a third grader,” Greenspan said.

“We’re cognizant of trying not to medicalize things that are a normal part of life,” Deanna Adkins, a pediatric endocrinologist and the director of the Duke Child and Adolescent Gender Care Clinic, said. “Early puberty is early, but it’s still normal in most cases. We do the best we can to not make a child feel like, ‘My parents are bringing me to the doctor because there’s something wrong with me.’ ”

Recently, a parent whom I will call R.—she asked that I not use her name, to protect her daughter’s privacy—phoned her pediatrician’s office because her seven-year-old had developed a breast bud. R., who is a college professor and lives in Brooklyn, spoke first with a nurse. “She said, ‘You’re the third or fourth mom this week who’s called about this. Puberty is starting earlier and earlier. It’s very normal, Mom.’ When we saw the pediatrician, it was the same thing: ‘Oh, Mom, it’s normal.’ ”

R. found the pediatrician’s response dismissive without being reassuring. “There was no wider analysis about the consequences related to her socialization at school, her relationships with boys and men—all these things that it opened up,” R. said. She was especially uneasy because her daughter has experienced unusual stressors in the last couple of years, including a concussion and her parents’ divorce. Adding the possibility of early puberty, R. said, “just feels like insult to injury—like, can we give this kid a childhood?”

I spoke with R. again after she and her daughter had a more satisfying appointment with a pediatric endocrinologist. “There was a straight-up acknowledgement, from the beginning, that this is a big deal. It was O.K. to think of this as something to be attentive to.” Now, mother and daughter await the results of blood tests and a bone X-ray; it’s safe to say that, of the two, R. is the more anxious. When they first broached the topic of early puberty, her daughter was excited. “Yes! Now I can get a bra!” she exclaimed. Puberty in a younger girl could be a simpler rite of passage, at times even a thrilling one, R. said, “if there wasn’t society out there to worry about.”

Even in the absence of an acute medical crisis, some families do decide to halt the process of puberty temporarily, with medication that blocks the release of sex hormones—most commonly, a drug called Lupron. Lupron is sometimes prescribed off-label to children with gender dysphoria, and, due to efforts in many states to limit or ban gender-affirming pediatric care, the drug has become controversial. A puberty blocker such as Lupron may inhibit bone mineralization, when calcium and phosphate act on collagen to increase bone mass; this process accelerates during adolescence. Anecdotal reports have proliferated for years about women who took Lupron for precocious puberty in childhood and went on to suffer osteoporosis, joint disorders, and chronic pain in adulthood, but most research on puberty blockers and bone health is reassuring. In any case, it is difficult to adjudicate concerns about any long-term effects when those concerns are weaponized by, say, the Arkansas state legislature, which is attempting to prohibit gender-affirming pediatric care in the state with a bill known as the Save Adolescents from Experimentation (SAFE) Act, or the state attorney general’s office in Texas, which has proposed that administering puberty blockers to children with gender dysphoria may constitute “child abuse.” (Studies have repeatedly shown that mental-health outcomes for L.G.B.T.Q. youth were disproportionately impacted by the pandemic, and advocates for trans young people have warned that the ongoing proliferation of anti-trans legislation will compound those effects.)

Adkins told me that she has not seen long-term issues such as low bone density or higher rates of fractures in patients who took Lupron. “When kids are in early puberty, they’re already starting to add calcium to their bones,” she said. “Pausing that for a period of time slows down their growth spurt and slows down their calcium spurt. But once you stop the medication, all of that restarts.” Children with precocious puberty typically stay on blockers until they reach a bone age of around eleven or twelve. “They’ll be accruing calcium in their bones from the restart of puberty all the way to the age of thirty or so,” Adkins said. “There’s plenty of time to catch up.”

There are two main criteria to consider when deciding to start a child on Lupron, Adkins told me. One is if the child’s projected adult height falls below the fifth-percentile range, due to rapid bone maturation; stalling puberty buys the kid more time to add some inches. The other is more subjective, and has to do with physical or developmental challenges that the child might face in addition to precocious puberty.

V., who is an occupational therapist in Orlando, has a daughter who is on the autism spectrum. She noticed that her daughter’s body began rapidly transforming in the late spring of 2020, when she was six and a half: breast buds, a huge growth spurt. By age eight, she had pubic hair and wore clothes in an adult-size extra-small. She frequently felt “off” in ways that she couldn’t precisely articulate—fatigued and headache-y. Her social status was changing, too. “She told me that boys were giving her more attention at school,” V. said. “She was like, ‘You’ve never noticed me before. Now, all of a sudden, I’m interesting? What?’ ”

V. brought her daughter to a developmental pediatrician and a pediatric endocrinologist; the latter was a four-month wait. An X-ray showed that her “bone age” outpaced her chronological age by about two years. Her doctor guessed that she might begin her period within a few months, which seemed too soon for her. In the spring, her daughter began taking Vitamin D supplements, which aid in calcium absorption. She received her first dose of Lupron in August, two months before her ninth birthday. “I felt as if she needed more time to work on her social-emotional skills before she had to deal with a period every month,” V. said. “I want her to feel like, ‘O.K., I’m ready for this.’ But honestly, I need some time to adjust, too.”

In Judy Blume’s 1970 young-adult novel “Are You There God? It’s Me, Margaret,” which has served as a puberty handbook of sorts for generations of girls, a character named Laura Danker looms awkwardly on the periphery. Laura is studious, very shy, and very tall. When the eleven-year-old narrator of the book, Margaret Simon, sees Laura on the first day of school, she mistakes her for a teacher, not a fellow sixth grader. “You could see the outline of her bra through her blouse and you could also tell from the front that it wasn’t the smallest size,” Margaret observes. “She sat down alone and didn’t talk to anyone.” Margaret has just moved to town and easily makes new friends, who giggle and gossip about “the big blonde with the big you know whats.” “She’s got a bad reputation,” one girl says. “She’s been wearing a bra since fourth grade and I bet she gets her period,” another alleges.

Laura’s body commands a chaotic attention from her peers: by turns affronted and leering, repelled and keenly envious. Her body provokes their imagination, then serves to corroborate whatever they might imagine. Laura belongs nowhere: a head taller than all the boys, arms crossed over her chest, feeling the shame and confusion of the eleven-year-old she is but does not look like.

In Blume, the fast-developing girl is sympathetic but mostly a cipher, a narrative device; in Elena Ferrante’s “My Brilliant Friend,” she gets to tell the story. In the book—the first of Ferrante’s Neapolitan Novels—young Lenù, the narrator, gets her period without knowing what it is; she is comforted by an older friend, who’s had hers for a year already. Lenù’s best friend, Lila, shows no signs of development; for this, Lenù seems to pity her. “Suddenly, she seemed small, smaller than I had ever seen her…she didn’t know what the blood was. And no boy had ever made a declaration to her.” For an instant, it doesn’t entirely make sense that they are peers, much less friends.

Lenù is wrung out by a classical pubertal funk: moodiness, anxiety, impulsivity (she flashes her breasts at some classmates for ten lire). Like Laura in “Are You There God?,” Lenù feels herself to be at once conspicuous and isolated. “I felt at the mercy of obscure forces acting inside my body,” she says. She is “besieged by boys.” She searches for respite. “I sneaked away, I compressed my bosom by holding my arms crossed over it, I felt mysteriously guilty and alone with my guilt.”

The stigma of early development in girls is particularly painful because, in some cases, it may perpetuate a vicious cycle. An article published in the Journal of Pediatric and Adolescent Gynecology, in May, found that early puberty put girls at higher risk for obesity, type-2 diabetes, breast cancer, and heart disease along with “depression, anxiety, eating disorders, and antisocial behaviors,” “earlier onset of sexual activity, higher number of sexual partners, and higher likelihood of substance use, delinquency, and low academic achievement.” The journal Hormones and Behavior, in 2013, argued that “early maturing girls are at unique risk for psychopathology.” A Pediatrics article titled “Early Puberty, Negative Peer Influence, and Problem Behaviors in Adolescent Girls,” from 2013, stated, “Early timing of puberty and affiliation with deviant friends are associated with higher levels of delinquent and aggressive behavior. Early-maturing adolescents tend to affiliate with more-deviant peers and appear more susceptible to negative peer influences.” (Free book-title idea for Elena Ferrante: “My Deviant Friend.”)

Kaplowitz, of Children’s National Hospital, and Greenspan both advised caution about the most doomsaying studies of girls who experience early puberty. Some of the results are derived from brief questionnaires. Others are based on self-reported data, which can render wobblier conclusions (for example, most women can pinpoint when their period began, more or less, but not as many know precisely when their breasts began to bud). “Many of these studies are not well controlled, and many of them don’t have a large number of subjects,” Kaplowitz said. “I don’t think these are settled issues.”

Because more Black girls enter puberty at a younger age, and because Black girls tend to come under more punitive surveillance no matter what Tanner stage they happen to occupy, the onus of early puberty can be especially harmful to them. A 2017 report from the Georgetown Law School’s Center on Poverty and Inequality studied the impact of “adultification,” a phenomenon in which children are socialized to act older than they are, and in which Black kids, specifically, are perceived as “less innocent and more adult-like than their white peers”—less in need, or less deserving, of the kinds of protections that childhood confers. Adultification has effects across the education and juvenile-justice systems: Black girls are more likely to be disciplined than white girls of the same age for the same infractions, and they have higher rates of school suspensions, referrals to law enforcement, and arrests.

The emotional and behavioral haywire of adolescence is driven by a pair of interlocking mechanisms: the hormonal and the social. The hormones that are released in puberty can lead to increased risk-taking and sensation-seeking; a nine-year-old who is newly doused in these hormones may not have the same self-regulating ability to manage them that a thirteen-year-old does. And just how much self-regulation an early-developing girl must exhibit depends on her surroundings: not just the scrutiny she receives from adults, which in turn is mediated by race and class, but by the tendencies of the children and young adults with whom she interacts. An older-looking girl might be more likely to hang out with actually older girls, and do the things they do.

Among the adverse outcomes linked to early puberty that are most strongly supported by data, causation is not always clear. “We know that people who have menarche earlier do tend to have a higher rate of depression,” Greenspan said. “But we don’t know if that’s a biological thing or a social thing. Is it the biological effects of estrogen on the developing brain? Or is it the stress of looking older than your peers, and having to deal with that?” Even the ways in which a girl looks older than her peers is heavily dependent on her social context. “Are you in a school with uniforms, where everybody looks kind of shapeless? Or are you in an environment where clothes are tighter, and everyone is looking at you? You might feel uncomfortable or even miserable in your body—and that could lead to depression, that could lead to body dysmorphia,” Greenspan said.