Add "Facebook depression" to potential harms linked with social media, an influential doctors' group warns, referring to a condition it says may affect troubled teens who obsess over the online site.
Researchers disagree on whether it's simply an extension of depression some kids feel in other circumstances, or a distinct condition linked with using the online site.
But there are unique aspects of Facebook that can make it a particularly tough social landscape to navigate for kids already dealing with poor self-esteem, said Dr Gwenn O'Keeffe, a Boston-area paediatrician and lead author of new American Academy of Paediatrics social media guidelines.
With in-your-face friends' tallies, status updates and photos of happy-looking people having great times, Facebook pages can make some kids feel even worse if they think they don't measure up.
It can be more painful than sitting alone in a crowded school cafeteria or other real-life encounters that can make kids feel down, O'Keeffe said, because Facebook provides a skewed view of what's really going on. Online, there's no way to see facial expressions or read body language that provide context.
The guidelines urge paediatricians to encourage parents to talk with their kids about online use and to be aware of Facebook depression, cyber bullying, sexting and other online risks. They were published in Paediatrics.
Abby Abolt, 16, a Chicago high school sophomore and frequent Facebook user, says the site has never made her feel depressed, but that she can understand how it might affect some kids.
"If you really didn't have that many friends and weren't really doing much with your life, and saw other peoples' status updates and pictures and what they were doing with friends, I could see how that would make them upset," she said.
"It's like a big popularity contest - who can get the most friend requests or get the most pictures tagged," she said.
Also, it's common among some teens to post snotty or judgmental messages on the Facebook walls of people they don't like, said Gaby Navarro, 18, a senior from Grayslake, Illinois. It's happened to her friends, and she said she could imagine how that could make some teens feel depressed.
"Parents should definitely know" about these practises," Navarro said. "It's good to raise awareness about it."
The academy guidelines note that online harassment "can cause profound psychosocial outcomes", including suicide. The widely publicised suicide of a 15-year-old Massachusetts girl last year occurred after she'd been bullied and harassed, in person and on Facebook.
"Facebook is where all the teens are hanging out now. It's their corner store," O'Keeffe said.
She said the benefits of kids using social media sites like Facebook shouldn't be overlooked, however, such as connecting with friends and family, sharing pictures and exchanging ideas.
"A lot of what's happening is actually very healthy, but it can go too far," she said.
Dr Megan Moreno, a University of Wisconsin adolescent medicine specialist who has studied online social networking among college students, said using Facebook can enhance feelings of social connectedness among well-adjusted kids, and have the opposite effect on those prone to depression.
Parents shouldn't get the idea that using Facebook "is going to somehow infect their kids with depression", she said. (AP, March 2011)