Quote from article:
Spending too much time in chat rooms and on social-networking sites? A number of studies now suggest that this can be associated with depression, particularly in teens and preteens. Internet addicts may struggle with real-life human interaction and a lack of companionship, and they may have an unrealistic view of the world. Some experts even call it "Facebook depression."
In a 2010 study, researchers found that about 1.2% of people ages 16 to 51 spent an inordinate amount of time online, and that they had a higher rate of moderate to severe depression. However, the researchers noted that it is not clear if Internet overuse leads to depression or if depressed people are more likely to use the Internet. (end of quote)