Facebook users report having negative feelings like frustration and envy after spending time online , says a new study from Germany.

The study included more than 500 people who used Facebook and researchers found that at least a third of the study participants had negative feelings like frustration. The study also found that people who use facebook to browse pictures, read wall posts or check newsfeeds are more likely to harbor negative feelings than people who actively participate on the networking platform.

Previous research has associated Facebook use with anxiety, debt and even higher weight. Whether or not Facebook increases depression is still open to debate. But almost everyone agrees that Facebook is addictive, and according to a study, sometimes even more than sex.

A recent study on facebook published in the journal Memory & Cognition had found that people are more likely to remember facebook status updates than lines from a book or even a person's face. Researchers who conducted the present study also found that about a fifth of all events that lead to envy among people were somewhere within the context of facebook. Researchers call this phenomenon as the "envy spiral" where envy leads a person to change his or her profile which in turn leads "others" to be envious.

The "envy provokers" in the present study (that was conducted in Germany) were photos and news of travel and leisure. Researchers found that people got envious when they saw pictures of a recent vacation that a friend had taken.

The study found that there is a negative association between feelings on envy among facebook users and their life satisfaction. Researchers plan to conduct similar research in groups of people belonging to different culture to see if culture differences influences the way people react to news that they get from their friends via facebook.