Children and teens who are bullied may be more likely to think about or attempt suicide, a new study from the Netherlands suggests.
Children in the study who had been bullied were twice as likely to have suicidal thoughts, and more than twice as likely to attempt suicide as kids who weren't bullied, according to the study, published online today (March 10) in the journal JAMA Pediatrics.
Notably, cyberbullying was even more strongly correlated with suicidal thoughts than traditional (in-person) bullying, the researchers said.
"Suicide is one of the most important causes of adolescent mortality," said study author Mitch van Geel, of Leiden University in the Netherlands. "We found that attempted suicides are significantly related to bullying, a highly prevalent behavior among adolescents."
Estimates suggest that between 15 and 20 percent of adolescents are involved in bullying, whether as a bully, a victim or both. [10 Facts Every Parent Should Know About Their Teen's Brain]
Between 5 and 8 percent of U.S. teens attempt suicide yearly, van Geel said. However, it's much less common for a teen to actually die by suicide — there are about 100 to 200 times more suicide attempts than completed suicides, according to a 2012 Centers for Disease Control and Prevention report on 15- to 24-year-olds.
In the study, the researchers analyzed 34 previous studies on the relationship between bullying and suicidal thoughts, and nine previous studies on the link between bullying and suicide attempts in young people.
The children and young adults ages 9 to 21 who were victimized were 2.2 times as likely to have suicidal thoughts as those who were not victimized, and bullying victims were 2.5 times more likely to attempt suicide, compared with nonvictims.
It isn't exactly clear why cyberbullying had a stronger impact than traditional bullying on a child's risk of having suicidal thoughts, the researchers noted.
"This may be because victims of cyberbullying feel denigrated before a wider audience, or because the event is stored on the Internet, they may relive denigrating experiences more often," van Geel said, adding that further research of the link is needed.
The new study is an important one, said Dr. Victor Fornari, director of child and adolescent psychiatry at North Shore-LIJ Health System in New Hyde Park, N.Y., who was not involved in the study.
"Suicidal thoughts and suicidal behavior are already serious concerns for adolescents, and if being a victim of bullying and cyberbullying increases the risk by two to three times, then it is a serious concern," Fornari told Live Science.
In the pre-Internet era, bullying was limited to school hours, but these days, modern technology lets bullying continue even when kids go home from school, Fornari said.
Because schools don't have control over children's Internet activities at home, educators often struggle with the issue of bullying accountability, Fornari said. For instance, there is no clear legislation delineating schools' responsibilities to protect victims when cyberbullying occurs off school grounds or after school hours, he noted.
Researchers are looking for effective ways to prevent bullying, van Geel said.