500 Facebook friends is not an unusually high number for the average young adult, but a recent survey of college students in Scotland found the more Facebook friends a person had, the more likely he or she was to be stressed out and anxious.
"Like anything else you have to maintain. The more you have of it, the more difficult it's going to be, the more anxiety it's going to provoke," says psychologist Dr. Scott Bea.
Dr. Bea agrees with the Scottish researchers who compare Facebook to a gambling addiction, where users are kept in a kind of "neurotic limbo", unable to tear themselves away for fear they'll miss out on something.
"If you walk away, you're afraid that some jackpot might occur while you're gone," he explains.
In the study, students who'd invested the most energy into Facebook and built the largest social networks said they did not come away with much of a reward.
In some cases students can't walk away.
"I do know some people who are on it constantly," says Facebook user Nathan Schelble.
"I know people who have trouble studying because of it, and they actually have to get their passwords changed by other friends," adds Iv Neov.
Facebook did not respond to requests for comment on the new study.