People who use Facebook to compare their friends' lives to their own may be at risk of experiencing symptoms of depression, a new study suggests.

US researchers set out to investigate if regular use of the popular social networking site could affect mental health.

They surveyed over 700 college students and found that using Facebook to simply stay connected with family and friends did not tend to result in any mental health issues.

However, users who engaged in ‘surveillance use' of Facebook were prone to feelings of envy, which could lead to symptoms of depression.

Surveillance use describes when users specifically check Facebook to see how their lives compare to their friends' lives. If they see posts about things like happy relationships, new cars, new houses or expensive holidays, this can lead to feelings of envy, which can eventually lead to symptoms of depression.

"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. 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," explained Prof Margaret Duffy of the University of Missouri.

The researchers found that overall, if people who use Facebook are envious of their friends' lifestyle and activities, they are ‘much more likely to report feelings of depression'.

"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 when using Facebook," Prof Duffy added.

Details of these findings are published in the journal, Computers in Human Behaviour.

For more information on depression, see our Depression Clinic here