How Early Puberty Affects Teen Mental Health

Why do some teens wind up with mental health and substance abuse problems? It’s something researchers have worked to explain over the years, pointing to everything from parenting styles to genetic predisposition.

Now a series of new studies confirms and adds nuance to another: early puberty — defined as before 8 in girls and before 9 in boys, which in girls especially, the researchers found, can increase the risk of winding up on psychiatric medicine.  

“Early puberty is associated with an increased risk of general psychological distress, in terms of lower self-rated health, psychiatric diagnoses and the use of psychiatric medication among young people. The trend is strongest for girls, but it also applies to boys,” says lead author Anne Gaml-Sørensen, part of Prof. Cecilia Ramlau-Hansen’s research group at the Department of Public Health at Aarhus University in Denmark.

“Our studies suggest that girls who enter puberty early may have twice the risk of receiving psychiatric medication for mental health conditions in general, compared with girls who begin puberty at the same time as their classmates. Among boys, we found only a slight increase in risk.”

The studies are based on cohort investigations in which a total of 15,818 Danish adolescents completed questionnaires on puberty, with follow-ups on early-puberty effects at age 18.

The fallout mostly affected girls — around 4% of whom received a diagnosis of anxiety and 12% of whom reported symptoms of social anxiety. The earlier the girls entered puberty, the higher the risk of receiving an anxiety diagnosis, with the risk 26% higher for each year earlier the puberty began.

And mental-health struggles were not the only downside, as risk-taking behaviors such as using alcohol, tobacco, and recreational drugs also increased.

“What we can also see is that earlier and more rapid pubertal development is associated with increased risk-taking behavior during adolescence. This may manifest itself in earlier and more frequent use of alcohol, tobacco and drugs,” explained study co-author Pernille Jul Clemmensen.

Earlier research, including a 2013 study out of the University of Florida, came to similar conclusions.

It’s all concerning, considering that girls around the world are entering puberty younger than before, according to Nature. In the 1840s, the average age of a girl’s first period was about 16 or 17; today, it’s around 12. The average age for onset of breast development fell from 11 in the 1960s to around 9 or 10 years in the U.S. by the 1990s. And it’s not so uncommon for the first hints of puberty — technically defined as when the brain’s hypothalamus starts producing the gondatropin-releasing hormone (GnRH) — to begin at 8 (at least for girls).

Possible reasons for the drop in puberty age range from obesity to exposure to hormone-disrupting chemicals or childhood stress.

“The trend has prompted the international organization the Endocrine Society to develop clinical-practice guidelines on puberty, to be published in mid-2026,” the Nature article reports. “The guidelines will reconsider how to treat girls on the border between typical and ‘precocious’ puberty, which has commonly been defined as before the age of 8 in girls, but that some specialists argue should be younger.”

Researchers behind the newest findings hope they will prompt parents and physicians to pay extra-close attention to the mental health and behaviors of kids who enter puberty early. But they also stress that more research is needed.

“These studies show that there is an association,” said Ramlau-Hansen. “However, further research is now needed to explore the mechanisms underlying these links — including biological, psychological and social processes.”