New York, Feb 4 (IANS): Facebook use can lead to symptoms of depression if the social networking site triggers feelings of envy among its users, researchers from the University of Missouri (MU) have found.

According to Margaret Duffy, professor and chair of strategic communication at the school of journalism, how Facebook users use the site makes a difference in how they respond to it.

"Facebook can be a fun and healthy activity if users take advantage of the site to stay connected with family and old friends and to share interesting and important aspects of their lives," Duffy said.

"However, if Facebook is used to see how well an acquaintance is doing financially or how happy an old friend is in his relationship - things that cause envy among users - use of the site can lead to feelings of depression,"she noted.

For the study, Duffy and Edson Tandoc, former doctoral students at the MU, surveyed young Facebook users and found that some of those who engage in "surveillance use" of the site also experience symptoms of depression while those who use the site simply to stay connected do not suffer negative effects.

Surveillance use of Facebook occurs when users browse the website to see how their friends are doing compared with their own lives.

The researchers found that Facebook postings about things such as expensive vacations, new houses or cars, or happy relationships can evoke feelings of envy among surveillance users.

These feelings of envy can then lead to Facebook users experiencing symptoms of depression.

"We found that if Facebook users experience envy of the activities and lifestyles of their friends on Facebook, they are much more likely to report feelings of depression," Duffy noted.

Facebook can be a very positive resource for many people, but if it is used as a way to size up one's own accomplishments against others, it can have a negative effect.

It is important for Facebook users to be aware of these risks so they can avoid this kind of behaviour while using Facebook, she concluded.