Cyber-bullying may be even tougher for kids to handle than "traditional" bullying involving beatings, name-calling or social shunning, researchers have found.

Researchers with the U.S. National Institutes of Health's Institute of Child Health and Human Development have found that kids who are the targets of cyber-bullying at school are at greater risk for depression than are the youth who bully them -- a contrast to findings on traditional bullying.

Past studies on traditional bullying show that "bully-victims" -- those people who both bully others and are bullied themselves -- are more likely to report feelings of depression than any other bullying group.

But cyber-bullies appear to be less depressed than their victims.

Cyber bullying involves written attacks or aggressive behaviors by email or posted on websites. The researchers think that the lack of face-to-face contact makes the dynamic of cyber-bullying different from traditional bulling.

In cyber attacks, victims usually don't see their harasser and may not even be able to identify them. That can make cyber-bullies feel vulnerable to repercussions.

Their victims, meanwhile, may be "more likely to feel isolated, dehumanized or helpless at the time of the attack," the study authors wrote in the Journal of Adolescent Health.

Jing Wang, Tonja Nansel and Ronald Iannotti reached their findings after analyzing data from a 2005/2006 survey that included 4,500 students from Grade 6 to Grade 10.

Students were asked about recent feelings of sadness, grouchiness, inability to concentrate, and sleep disturbances. They were also asked whether they were involved with bullying, whether as perpetrators or victims.

The researchers classified bullying others or being bullied "two or three times a month" as frequent, and "only once or twice" as occasional. Respondents were further classified as either: bullies, victims, or bully-victims.

They found:

  • For physical bullying, no differences were found in depression scores among bullies, victims, or bully-victims.
  • For verbal and relational bullying, victims and bully-victims reported higher levels of depression than bullies.
  • For cyber bullying, frequent victims reported significantly higher levels of depression than frequent bullies and marginally higher depression than frequent bully-victims.

Dr. Iannotti, the study's senior author, notes that bullying interferes with scholastic achievement, development of social skills, and general feelings of well being.

In a study published last year, Dr. Iannotti's team reported that the prevalence of bullying among U.S. youth was about 21 per cent. Of those who had been bullied at least once in the last two months, 53.6 percent had been bullied verbally, 51.4 percent bullied socially (excluded or ostracized), and 13.6 per cent were cyber-bullied.