We’ve all been there. You’re feeling pretty chipper before you meet your friend for lunch – but within minutes, it’s clear that she’s not in a good mood. Perhaps she’s stressed about work, or her relationship is in trouble, or her shower is broken and her landlord won’t fix it. Whatever the reason, by the time you say goodbye, you’re feeling pretty bad-tempered yourself.

If you feel like you’re often susceptible to ‘catching’ your friends’ emotions (when they’re up, you’re up; when they’re down, you’re down), you’re not alone. According to a new study by researchers at the University of Warwick, both good and bad moods are prone to ‘spreading’ across friendship networks like emotional infections.

The team analysed data from a major study of US teenagers for the study, published recently in the journal Royal Society Open Science. They found that people with more friends who suffered from bad moods were more likely to experience low moods themselves, and were less likely to feel happier over time.

In contrast, adolescents with more positive social circles – that is, friends who were generally happy – were more likely to feel upbeat, and less at risk of feeling low.

This is how your friends’ bad moods can affect your own mental health