MONDAY, June 22, 2015 (HealthDay News) -- A new review suggests that estimates of cyberbullying are all over the place, ranging as low as 5 percent and as high as 74 percent.
But some findings are consistent: Bullied kids are more likely to be depressed and to be female, and cyberbullying mostly arises from relationships.
"When children and youth are cyberbullied, they are often reluctant to tell anyone," said review author Michele Hamm, a research associate with the Alberta Research Center for Health Evidence at the University of Alberta in Edmonton, Canada.
"Prevention and management efforts are likely necessary at multiple levels, involving adolescents, parents, teachers and health care professionals," Hamm said.
Researchers launched the review to get a better understanding of cyberbullying, which they defined as bullying via social media and not in private conversations by text messages or Skype.
"We wanted to find out whether there was evidence that social media could be harmful to kids and if so, be able to inform future prevention strategies," Hamm said.
The researchers looked at 36 studies, mostly from the United States. Of those, 17 reports examined how often cyberbullying occurred. The researchers found that a median of 23 percent of kids reported being bullied via social media. A median is not an average; it's the midpoint in a group of numbers.
The percentage is derived from studies that had a wide variety of definitions of when cyberbullying had to have occurred to count, Hamm said. In some cases, researchers counted whether kids had ever been bullied; in other cases, bullying only counted if it was repeated, she said.
One expert thought 23 percent was probably an accurate assessment of the prevalence of cyberbullying.
"It would be easy, just from watching the news, to conclude that virtually every child in America is a victim of bullying," said Robert Faris, an associate professor of sociology at the University of California, Davis.
"The prevalence of cyber- and traditional bullying will always vary based on the way they are defined, how the questions are asked and the time period in question," Faris explained. "But regardless of these issues, only a minority of kids can be considered victims. So, the overall estimate is actually in line with other estimates of traditional bullying."
The researchers also found an association between depression and cyberbullying, although it's not clear if one causes the other.
"The associations between cyberbullying and anxiety and self-harm were inconsistent," Hamm added. "Except for one, all of the studies that we found were only looking at relationships at one point in time, so it isn't known whether there is a long-term impact of cyberbullying on kids' mental health."
However, Faris believes cyberbullying by social media poses a special threat to kids and is "probably a lot more damaging to targets" than other forms of bullying. "Harassing messages can be blocked, but public humiliation can't be halted by victims," he said. "And, of course, it involves a much wider audience."
As for helping kids who are bullied, review author Hamm said, "Adolescents are often unaware that anything can be done about cyberbullying, so efforts should be made to increase education regarding how to address it and who to tell, focusing on both recipients and bystanders."
Rachel Annunziato, an assistant professor of clinical psychology at Fordham University in New York City, said, "The best advice we can give parents is to frequently monitor their children's Internet use... We are in a position to spot and stop this behavior or help our children if they are recipients of cyberbullying. Another thing we can do is ask about cyberbullying. Our children may not realize that we are aware of this."
Faris agreed that parents must play a role.
"Kids do not tell adults about bullying. Not teachers, not coaches, not parents," he said. "This is largely because they feel adults will not help and can make things worse. So, one crucial lesson is that parents should really monitor what their kids are doing online and on social media, and also ask pressing questions about how things are going at school and with friends."
The study was published in the June 22 online edition of JAMA Pediatrics.
For more about cyberbullying, go to stopbullying.gov.