Self-injury among teens is more common than thought, a new study suggests.

Some 46 percent of high school students surveyed said they had purposely injured themselves more than once in the past year. Among those who said they had injured themselves, more than half said they had cut or burned their skin or given themselves a tattoo or engaged in other acts the researchers labeled as serious. Others engaged in comparatively minor acts such as pulling out hair, biting themselves or picking at areas of the body until they bled.

Many parents are unaware that teens engage in "cutting" and other forms of self-injury.

The study

For the study, the researchers surveyed 633 students in grades 9–12 from schools in the southern and midwestern United States. The survey questions were designed to reveal the incidence of non-suicidal self-injury (NSSI), which is the deliberate, direct destruction of body tissue without conscious suicidal intent.

The participants were allowed to respond anonymously, but self-reporting of this nature is still thought to generate less than perfect data. Still, scientists were surprised by the results.

“The findings are important because it suggests that NSSI is more prevalent among adolescents in the general population than previously thought,” said study leader Elizabeth Lloyd-Richardson, a psychologist at The Miriam Hospital in Rhode Island and an assistant professor at Brown University. “If this is the case, it’s essentially a wake-up call to take better notice of these behaviors in the community and learn how to help teens manage stress without harming themselves.”

The research is published in the August issue of the journal Psychological Medicine.

Why they do it

Cutting and burning of skin could suggest more severe outcomes, the researchers say.

The survey also asked why the participants do it. The most common reasons: to get control of a situation, to stop bad feelings, and to try and get a reaction from someone.

“Once thought of as a phenomenon only found in teens with mental health issues, the results support the notion that many adolescents in the community are self-harming as way to cope with emotional distress," Lloyd-Richardson said.

In a British study last year of more than 6,000 15- and 16-year-olds, 11 per cent of girls and 3 per cent of boys reported hurting themselves in the previous year.

Last year, Cornell and Princeton University researchers surveyed 3,069 college students on self-injury. They found that about 17 percent (20 percent of women and 14 percent of men) have cut, burned, carved or harmed themselves in other ways. Most did not seek help from medical or mental health professionals, the researchers found.

The college students who engaged in self-injury were nearly twice as likely to have considered or attempted suicide, the researchers said, highlighting the need for further study and the development of intervention strategies.

Talking about it

A separate Cornell University study last year found about 500 Internet message boards for adolescents who injure themselves. An analysis of the comments suggested both positive and negative potential outcomes.

"Internet message boards provide a powerful vehicle for bringing self-injurious adolescents together, and to a great extent, they provide a safe forum and a source of valuable support for teens who might otherwise feel marginalized and who may be struggling with shame," said Janis Whitlock, director of the Cornell Research Program on Self-Injurious Behaviors.

But the boards can also encourage self-injury.

"Easy access to a virtual subculture of like-minded others may reinforce the behavior for a much larger number of youth," Whitlock said.