A slew of recent studies found the site causes some people to become depressed. And a new paper contends the site appeals to people with far more serious psychiatric problems......those who most often “like” other people’s activities on Facebook are more likely to show symptoms of “mania” and “compulsivity.”Why are many "likers" depressed? "People who 'like' friends’ updates and pictures may do so in the hope that the favor is returned"---but the liking is often not reciprocated.
Facebook Depression (American Academy of Pediatrics article here) can also be triggered in children and teens "when poring over positive status updates and pictures of happy friends." Whatever the reasons, the after-effect of logging in to Facebook is not a pleasurable experience for a sizable population.
Addictions (e.g., gambling, drugs, etc. and now Facebook?) that leave people feeling bad eventually peak as the flow of exiting customers rises. Unless the company addresses this effect of its product, the growth in Facebook customers may come to a halt a lot sooner than anyone expects.