At age 14 or 15, a perfect storm of surging hormones, immature brains and unfamiliar emotions drive nearly one in 12 teens to deliberately hurt themselves, most often by cutting or burning their own flesh, or by trying to hang, electrocute, drown or suffocate themselves.
"The window of vulnerability for this experience of self-harm appears to open at around puberty," said Dr. Paul Moran, co-author of a study about self-harm published online Wednesday in The Lancet.
Teens, he said, may hurt themselves to block out emotions "they feel to be intolerable." At particular risk, he said, were teens "on a fast-track to adulthood, those kids who are at the margins at school, who are engaged in early sexual activities, who are using alcohol and drugs at a young age."
Families, educators and even self-injuring youngsters may be relieved to hear that in 90 percent of cases, these frightening, aberrant practices resolve on their own, said Dr. Niall Boyce, a psychiatrist and senior editor of The Lancet. "As with many situations, it is the lack of knowledge that is the root of this fear," Boyce said at a news conference in London highlighting the study's key findings.
Moran, from the Institute of Psychiatry at King's College London, and co-author Dr. George C. Patton, from the Center for Adolescent Health at the Murdoch Children's Research Institute in Melbourne, Australia, said they believed theirs was the first large study to trace "the natural history" of self-harming behavior from its onset in puberty through young adulthood. They pointed out that self-inflicted deaths, including suicides, rise sharply during that same period.
The study authors sought to identify the environmental and biological factors that influence young people's impulses to hurt themselves, which could guide strategies "to prevent further self-harm," Boyce said. He described the new research into the global problem of self-harm as "extremely exciting, extremely interesting. It gives us an idea of how this problem develops."
Moran, Patton and their fellow researchers studied a random group of nearly 2,000 school children, ages 14 and 15, in the Australian state of Victoria, from August 1992 through January 2008. Over the course of those 15 years, and on as many as nine occasions, the students answered questions to assess if, and how often, they'd engaged in self-harm. Anyone who answered affirmatively when asked if they'd "ever deliberately hurt yourself or done anything that you know might have harmed or even killed you?" was asked to describe the episodes.
Moran said their answers, and the years of observing them, yielded several important insights:
Self-harm is common, reported by about 8 percent of 14- to 19-year-olds.
At every stage, more girls reported self-harm than boys.
Those who cut, burned or otherwise deliberately hurt themselves were more likely to be seriously depressed or anxious, and to report smoking, drinking or abusing drugs. Similarly, a small subgroup of students who began hurting themselves as young adults were more likely to report having been depressed or anxious as teenagers.
The proportion of young men and women reporting self-harm substantially declined as they aged.
Teenage self-harmers often have "serious emotional difficulties" and need help and support, lest they suffer persistent problems later in life, Moran said. Therefore, he said, adults "living and working with young people" need to be able to spot the signs of "persistent distress."
Social Environment Can Encourage Self-Harm, or Protect Against It
The social environment can exert a positive, or in some cases a negative influence on youngsters prone to self-harm. For example, experts in adolescent mental health increasingly talk about the contagious effect on girls of exposure to other cutters, whether friends or acquaintances found through the Internet.
On the positive end, though, Patton suggested that "social scaffolding" can be a bulwark against self-harm. "Young people are going to be most protected from self-harm by good connections, and good involvement with their families ... with schools, engagement with their local neighborhood, and good relationships with their peers."
At the news conference, Keith Hawton, director of the Center for Suicide Research at Oxford University, and co-author of accompanying commentary in The Lancet, said the latest study captured part of "a hidden population" in the community, where many never seek professional help. Unlike self-harmers who land in hospitals after overdosing, self-harmers living under the radar in the community tend to hurt themselves in other ways, often known only by their closest friends.
With an estimated 6 percent to 10 percent of all teenagers engaged in self-harm, "the numbers are huge. It represents much distress," he said.
"The crucial question is: what is the significance of self-harming behavior in these mid-teenage years for subsequent mental health and future self-harming behavior, and indeed suicide?" Hawton said. He credited Moran and his colleagues with making "a special contribution" to what's known about the influence of self-destructive teenage behavior on future mental health.