(Reuters Health) - In any given year, roughly one in four girls in U.S. high schools and one in 10 boys try to harm themselves even when they are not attempting suicide, a recent study suggests.

So-called non-suicidal self-injury has long been more common among girls than boys, but the current study offers fresh evidence that the problem is widespread for youth of both sexes.

While the study found a history of suicide attempts and suicidal thoughts may make self-harm more likely, the results also suggest that other events like being a victim of rape or cyberbullying can increase the risk.

Researchers surveyed more than 64,000 male and female high school students in 11 U.S. states. Almost 18 percent reported at least one episode of self-injury in the previous year, according to a report in the American Journal of Public Health.

“Self-injury is surprisingly common among adolescents,” study leader Martin Monto of the University of Portland, Oregon, said by email. “For teens who are grappling with this issue or parents who are responding to it, they are not alone.”

Girls were roughly twice as likely as boys to report self-harm.

Girls were also more likely to report risk factors for self-injury like depression, suicidal thoughts, or being a victim of rape or cyberbullying.

Teens who reported being forced to have sex at any point in their lives were 56 percent more likely to report self-injury in the previous year than youth who hadn’t had a nonconsensual sexual experience, the study found.

Adolescents who reported being bullied online in the past year were more than twice as likely to report self-injury in the same period than teens who were not cyberbullying victims, the study also found.

Gay, lesbian and bisexual teens were also more than twice as likely to report self-injury over the previous year compared to youth who identified as heterosexual.

And teens who had contemplated suicide were almost three times more likely to report self-injury than those who didn’t consider killing themselves. Planning a suicide made the risk of self-injury even higher.

The study included high school students from Arizona, Connecticut, Delaware, Florida, Idaho, Kentucky, Massachusetts, Nevada, New Hampshire, New Mexico and Vermont.

Among boys, rates of intentionally harming themselves without trying to die ranged from a low of 6.4 percent in Delaware to a high of 14.8 percent in Nevada.

For girls, rates of purposefully harming themselves without attempting suicide ranged from a low of 17.7 percent in Delaware to a high of 30.8 percent in Idaho.

The study was not a controlled experiment designed to prove whether or how specific factors might influence the potential for teens to report self-harm or the differences between boys and girls. It’s also possible that the results might not reflect trends across the rest of the country.

It’s possible, too, that gender norms in the U.S. and the way the survey asked about self-harm might explain some of the differences between boys and girls in the study, said Nicholas Westers, co-author of an accompanying editorial and a researcher at Children’s Medical Center Dallas and the University of Texas Southwestern Medical Center.

The survey gave two examples of self-harm - cutting and burning - and girls may do these things more often than boys, Westers said by email. Boys may be more likely to do other types of self-injury, like hitting or punching themselves or getting into fights with the intention of getting hurt, that aren’t always recognized as self-harm.

“In short, there really is no one reason for these gender differences of which we are aware,” Westers said. “A lot of research has not found any gender differences at all.”

SOURCE: bit.ly/2MIntTb and bit.ly/2LQ69Qf American Journal of Public Health, online July 11, 2018.