As your number of Facebook friends increases, your stress level may rise as well.  Researchers at the Edinburgh Napier University interviewed about 200 college students, and and 175 online participants, and found that the usefulness of the site can be overshadowed by the stress it causes.

Read more to find out why Mark Zuckerberg is to blame.

Facebook users that have more friends tend to invest more time in social networking.  Anxiety can also stem from worry about un-friending or being un-friended, pressure to be creative and entertaining, and users tend to worry that while some content may be appropriate for select friends, it may not be the type of thing they want family to see.

Additional findings, published by ZDNet:  

  • 12 percent of respondents said that Facebook made them feel anxious. Of these, respondents had an average of 117 friends each. The remaining 88 percent of respondents, who said that Facebook did not make them feel anxious, had an average of 75 friends each.
  • 63 percent delayed replying to friend requests.
  • 32 percent said rejecting friend requests led to feelings of guilt and discomfort.
  • 10 percent admitted disliking receiving friend requests.