Cyberbullying is not a new phenomenon. But an alarming number of teenagers are anonymously posting mean things online — about themselves.

About 6% of kids from the ages of 12 through 17 have bullied themselves digitally, according to research conducted by Sameer Hinduja, a professor of criminology at Florida Atlantic University and co-director of the Cyberbullying Research Center.

“It’s a new phenomenon, and this is definitely happening" for teens across the U.S., Hinduja said. “We have a tendency to demonize the aggressor, but in some cases, maybe one out of 20, the aggressor and target are the same.”

This issue was brought to researchers' attention by the death of Hannah Smith, a 14 year old from Leicestershire, England, who hanged herself after months of apparent online harassment.

After her death, officials from Ask.fm, a social media site where users can ask each other anonymous questions, found that 98% of the messages sent to Smith came from the same IP address as the computer she used.

Many other sites like Tumblr and the now defunct Formspring also have had an anonymous question feature, which could allow teens to anonymously send themselves hurtful messages and then publicly respond.

Researchers are calling this behavior "digital self-harm." Teens who identified as non-heterosexual were three times more likely to bully themselves online, while victims of cyberbullying were 12 times more likely to cyberbully themselves.

A strong link already exists between physical self-harm and suicide attempts, and researchers are concerned that the same connection could exist with digital self-harm.

“It could betray suicidal tendencies and lead to suicidal behavior down the line if it’s not addressed,” Hinduja said.

This is concerning because teen suicide rates have been steadily climbing over the past decade. The suicide rate for girls ages 15-19 doubled from 2007 to 2015, reaching its highest point in 40 years, according to the Centers for Disease Control and Prevention.

The question perplexing researchers is why teens would do this.

When asked why they engaged in digital self-harm, boys were more likely to say they did it as a joke or to get attention, while girls often said they did it because they were struggling with depression.

"There's that same phenomena that's going on; it's akin to physically wanting to feel pain," said Patricia Cavazos, an associate professor of psychiatry at the Washington University School of Medicine.

The rates of physical self-harm are similar, as well. About 8% of children ages 7-16 surveyed in a 2012 study said they'd engaged physical self-harm, or non-suicidal self injury.

There is a growing body of evidence that suggests social media plays a role in increasing mental health issues among young people, she said.

Cavazos, who studies depression-related content on social media, said more than likely teens are looking for a response. But peers often ignore posts that may indicate someone is struggling with mental health problems.

"These individuals could be at a very vulnerable place, and there's a risk of what could happen next if there is no intervention," she said. "The question is, what is the appropriate response when content like this is posted?"

Cavazos recommended sending a private message, encouraging them to seek professional help or getting a trusted adult involved, but she said more research needs to be done on how best to intervene.

Study author Hinduja said he hopes his research into digital self-harm will open up a dialogue about the issue.

“It’s extremely hard because kids are very hesitant to discuss these sorts of feelings and struggles,” he said. “As more educators and parents bring this up as a phenomenon, it will lead to more candid discussion.”