Scrolling through Facebook can leave people feeling worse afterward, the social network has admitted.

David Ginsberg, Facebook's director of research, and Moira Burke, research scientist, made the surprising admission on Friday in a blogpost that highlighted the downsides of using the website.

They detailed research from University of Michigan, which found that students randomly assigned to read Facebook for 10 minutes were in a worse mood at the end of the day than those who talked to friends or posted on the website.

They also revealed how a study from UC San Diego and Yale found that people who clicked on about four times as many links as the average person, or who liked twice as many posts, reported worse mental health than average.

"Though the causes aren’t clear, researchers hypothesise that reading about others online might lead to negative social comparison and perhaps even more so than offline, since people’s posts are often more curated and flattering," Facebook said.