Next time you think about cheering somebody up when they are upset, perhaps it might be best to just leave them alone.

Trying to make somebody smile when they are miserable could actually make them feel worse, a study has found.

If you force a friend to grin when they are in a bad mood then their brain starts to associate it with sadness instead of joy.

And next time they smile it could bring back miserable memories instead of lifting the bad mood.

It was carried out by Anirban Mukhopadhyay, an associate professor of marketing at Hong Kong University Science and Technology, who said you should wait until your unhappiness lifts before attempting a grin.

The study results showed that if you are faking a smile then it won’t cheer you up and that you are just using it to ‘mask’ your inner sadness.