Emma Mills-Rittmann quit Facebook because, she says, other kids ruined it for her.
“[Your friends] hang out with other people and they didn’t call you,” said the 14-year-old, who goes to St. John the Baptist Catholic School in Savage. “Then you see the pictures.”
Minnetonka teen Allison Jensen knows the feeling. “When you see albums of people with all their friends and you’re not in them, it kind of makes you feel left out,” said the 13-year-old, who goes to Hopkins West Junior High.
Reactions like those are something researchers and pediatricians are watching closely as they try to understand a new cyber ailment — “Facebook depression.” Facebook’s pervasive reminders of their friends’ happiness can amplify the sadness other teens may be feeling, the American Academy of Pediatrics reported this spring.
Those cheerful words in Facebook status updates, happy faces smiling from photos or the climbing numbers of friend tallies can make teens feel lonely, inadequate or just plain sad. The problem is made even worse in the summer, when teens have more free time.
Categories: Alternative Medicine, Health, Internet, Preventive Medicine, Psychology, Technology

As a pediatrician I am a witness to this fact on daily basis.
Thank you so much for sharing this information with us, before every one gets carried away with Facebook, without realizing that every thing that glitters is not gold.
Some other areas of concern with Facebook:
http://www.peoplemanagement.co.uk/pm/articles/2011/07/nurses-warned-over-use-of-social-media.htm
http://www.thejakartaglobe.com/blogs/is-technology-hurting-our-way-of-thinking/450650
There was an interesting story out of Switzerland.
A young lady of 15 was selected for a apprenticeship position in the local council. 150 had applied and she was selected.
Later on the job offer was withdrawn, because the girl had written a comment on a photo on facebook. Her teacher was sitting on a wooden box. She wrote that ‘surely her bum does not fit into the box’ (something like that. It was rude in German).
The potential employers representative also thought it ‘odd’ that the girl had already 700 ‘friends’.
Employers more and more do check facebook pages also when hiring. This is another trick, if a person has too many ‘friends’ it may be considered that he/she is wasting too much time on facebook. If he/she does not have so many one may wonder whether the applicant is sufficiently ‘social’.
In other words: Yes, to be ‘careful’ is one thing, but to keep away is better!