Posted: May 21, 2013 8:49 PM by Michelle Castillo - CBS News
Children and teens who had a peer commit suicide may be more likely to think about and attempt suicide themselves, an effect that appears to be more pronounced in younger kids.
The phenomenon, which is known as "suicide contagion," was shown to last two years or more after a peer's death, a Canadian study revealed.
"When these kids are suddenly faced with a suicidal death in their own age group, vulnerable kids may start thinking about suicide as a solution to their problems for the first time in their lives," study author Dr. Ian Colman, Canada research chair in mental health epidemiology, told the Toronto Star.
Suicide is the third-leading cause of death for people between age 10 and 24 in the U.S., according to the Centers for Disease Control and Prevention. About 4,600 youth in that age group die annually by taking their own lives, and 157,000 adolescents receive medical attention in a facility's emergency department for self-inflicted injuries. Eighty-one percent of 10 to 24-year-old suicides are males, and 19 percent are females.
The CDC reports that a national survey showed that 16 percent of students between ninth and twelfth grades contemplated suicide, 13 percent made a plan and 8 percent had attempted suicide in the year before being surveyed. Girls are more likely to report attempting suicide than boys.
An October 2012 study in the Archives of Pediatric Medicine revealed that bullied teens are 2.5 times more likely to think about suicide than those who haven't been harassed recently.
Researchers studied data from Statistics Canada's National Longitudinal Survey of Children and Youth, which included more than 22,000 children between 12 and 17 years old. They were asked a series of questions about if they knew someone who committed suicide, how close they were to the person, whether they thought about killing themselves and whether they had attempted it.
By the time participants turned 17, 24 percent of the group had a schoolmate who committed suicide, and 20 percent personally knew the person.
Children between 12 and 13 years old were five times more likely to think about suicide if they knew someone who killed themselves, compared to those who didn't know anyone who committed suicide. About 7.5 percent of adolescents of those ages who knew someone who took their own life attempted suicide themselves, but only 1.7 percent of those who didn't know anyone that took their own life tried it.
Fourteen to 15-year-olds were three times as likely to consider suicide if they were exposed to it, while 16 and 17-year-olds were twice as likely if a peer had ended his or her own life.
For both groups, rates of suicidal thinking and attempts were about the same whether the subject knew the deceased or not. The profound "suicide contagion" effect lasted for quite some time, so the authors suggested that schools provide suicide prevention studies for at least two years following the death of a classmate.
Frank Zenere, a school psychologist at the Miami-Dade County public school system, told Reuters Health, that people who didn't know the victim personally may actually be at the greatest risk. He was not involved in the study.
"Sometimes the closest friends are not the ones that are most likely to harm themselves because they're so up close and aware of the painful fallout with the family of the deceased, which can actually be a protective factor," Zenere said.
He added that younger children are more likely to be influenced by other people's actions.
"There's a lot more drama in middle school grade levels, they tend to have much more of an emotional outpouring, early teens versus late teens," he said.
In an accompanying editorial, Dr. India Bohanna, a mental health research fellow at the School of Public Health at James Cook University in Cairns, Queensland, Australia, wrote that the study confirms that exposure to suicide increases future suicidal behavior in other youth.
"The idea that suicide is contagious has always been controversial for various reasons; however, this important study should put many, if not all, doubts to rest," she wrote. "A unified and concerted effort now needs to be directed toward developing evidence-based postvention strategies. We need to know what works in mitigating the risk of contagion and why."
The study was published in the Canadian Medical Association Journal on May 21.
© 2013 CBS Interactive Inc. All Rights Reserved.