FRIDAY, July 15 (HealthDay News) -- More than half of the parents of teen-agers say they're worried about cyberbullying, a new survey finds.

Cyberbullying, which usually means one teen or group of teens taunting or spreading rumors about a peer online, has risen along with accessibility of the internet and the popularity of online social media such as Facebook.

In a survey of more than 1,000 parents of teenagers aged 13 to 17 by the American Osteopathic Association found that 85 percent of those polled reported that their children had social media accounts. About 52 of parents said cyberbullying was a concern.

One expert said these concerns are valid.

"While bullying through physical intimidation has long been a problem among teenagers, cyberbullying by using computers and smart phones to send rumors or post cruel messages has become more prevalent in recent years," explains Dr. Jennifer Caudle, an osteopathic family physician in Little Rock, Ark. and bullying expert, in a news release. "Even though there might not be physical injuries, cyberbullying leaves deep emotional scars on the victim."

The survey also revealed that one in six parents knew their child had been the victim of a cyberbully. Some of the kids teased or harassed online were as young as 9 years old. In most cases, the cyberbullying was not a one time occurrence, but rather happened repeatedly.

Cyberbullying can lead to anxiety, depression, loss of interest in socializing, aggression toward others the victim can bully, poor academic performance, and suicidal thoughts, Caudle said.

Some victims of cyberbullying have even killed themselves, according to the Cyberbullying Research Center, an organization run by professors from Florida Atlantic University and the University of Wisconsin who have studied the issue since 2002.

The vast majority of parents -- 91 percent -- believe they, not teachers, are ultimately responsible for preventing these long term effects. More than 75 percent of parents said they have discussed cyberbullying with their children, while 86 percent said they joined their child's online social network so they can monitor their teens' interactions. Two out of three parents also said they monitor the security settings on their children's social media accounts.

The survey also found that one in seven parents have barred their children from using online social media, but keeping teens off these networking sites may prove more difficult. Although just about all teens, or 97 percent, access their accounts from a home computer, many also log on using smart phone or mobile devices.

Girls are the worst offenders, the survey showed. About two-thirds of cyberbullying occurred among girls, making it twice as common among girls than boys. This fact may not be lost on parents. More than 75 percent reported they felt this type of aggressive behavior was a greater concern for girls.

More information

The National Crime Prevention Council provides more information on cyberbullying.