A new study finds people who use Facebook often tend to have an unhappy mood.
More than 80 college-age volunteers were questioned.
Researchers asked them five times a day what they were doing, how they were feeling, and if they had used Facebook recently.
The more participants logged onto Facebook, the more their mood dropped.
Their sad feelings existed no matter how many friends they had, or how supportive their friends were.
The study didn't include why Facebook put people in a bad mood.
It's speculated that social networking could make people feel inadequate or jealous of their friends.