(Reuters Health) - About a quarter of adolescents experience cyberbullying through social media, according to a fresh look at some past research.

Much of that past research also found links between cyberbullying and depression, the researchers write in JAMA Pediatrics.

"Social media use is so common among kids and adolescents," said Michele Hamm, the review's lead author from the University of Alberta in Canada. "We wanted to look at if there are documented harms associated with its use."

She and her colleague cite a 2012 report that 95 percent of American teenagers use the Internet. About 81 percent also use social media, it found.

While social media websites, such as Facebook and Twitter, allow for extended social time with people, they also provide an environment for repeated and sustained harassment.

For the review, she and her colleagues analyzed data from 36 studies of cyberbullying on social media. The participants were mostly U.S. middle and high school students ages 12 to 18.

On average, about 23 percent of participants reported cyberbullying, but those rates varied among the studies from 11 percent to about 43 percent.

Relationships were the most commonly cited reason for cyberbullying. Girls were also most likely to be on the receiving end of the cyberbullying, they found.

"Most of the kids used very passive coping strategies," Hamm told Reuters Health. Those strategies included blocking the bully, not reporting the bullying and just ignoring the abuse.

While there were no clear links between cyberbullying and anxiety, self-harm or suicide, there was a consistent link to depression.

The studies just captured one point in time, "so we don’t know what happened over a longer period of time," Hamm said.

For example, they don't know whether the link between cyberbullying and depression lasts into early adulthood or even later.

Hamm said it's important to encourage open communication between adolescents and their parents.

Let kids know "there are things that can be done about cyberbullying," she said. "They don’t have to be scared."

Hamm also said adolescents may not want to report cyberbullying because they're afraid their Internet access will be taken away.

Instead of restricting access, she said parents should encourage the safe use of social media.

The next step is to see whether cyberbullying impacts adolescents over a longer period of time, Hamm said.

(Reporting by Andrew M. Seaman)