Facebook is meant to foster pleasant social interactions, but a new study suggests it could be making us unhappier - and unhealthier - in the long run. Katie Wright looks at the evidence

Who doesn't love it when a hilarious quip, hot new profile picture or scintillating link posted on their Facebook page attracts a flood of likes and comments?

Scientists have shown that each little blue thumb you garner releases a hit of dopamine in the brain, but new research suggests those tiny bursts of happiness can have a detrimental effect over time.

A study from Yale and the University of California tracked 5,200 adults over three years, looking at their Facebook use, physical and mental health, and general wellbeing, as well as their real-world social interactions.

The results showed that for every 1% increase in likes, clicks on links and status updates on the social network, participants reported a decrease in self-reported mental health of between 5% and 8%.

That doesn't mean you should immediately delete your profile to stop yourself from spiralling into a deep depression, though.

Researchers Holly Shakya and Nicholas Christakis admit that the pattern observed may, in part, "stem from the simple fact that those with compromised wellbeing may be more likely to seek solace or attempt to alleviate loneliness by excessively using Facebook in the first place".

Indeed, other studies have found that online social connections can be a worthwhile source of support and help to lower stress.

On the health front, it's not great news, though, as the study found "a strong correlation between Facebook use and higher BMI [Body Mass Index]".

But, as with the wellbeing result, analysis suggests people with a higher BMI may be more frequent Facebook users to begin with, rather than social media use causing them to put on weight.

Even with caveats included, however, the paper concludes that Facebook use "does not promote wellbeing" - but it's up to you to recognise when your digital habits become a damaging compulsion rather than a healthy addendum to your real social life.

If that happens, the researchers advise, "individual social media users might do well to curtail their use of social media and focus instead on real-world relationships".