New research suggests that having joyful friends could combat depression, HealthDay reported.

Researchers from the Universities of Manchester and Warwick found that healthy mood spreads, depression does not. This means that being friends with someone who is depressed does not put others at risk of becoming depressed yourself and it is likely for them to help the depressed person recover. This is important as there is stigma attached to being depressed.

"We know social factors, for example living alone or having experienced abuse in childhood, influences whether someone becomes depressed. We also know that social support is important for recovery from depression, for example having people to talk to," Dr. Thomas House, one of the authors of the study, said in a statement. "Our study is slightly different as it looks at the effect of being friends with people on whether you are likely to develop or recover from being depressed."

For the study, researchers looked at more than 2,000 adolescents in a network of American high school students to see how their mood influenced each other by modeling the spread of mood using similar methods to those used to track the spread of infectious diseases, Yahoo News reported

They found that while depression does not "spread," having enough friends with healthy mood can halve the probability of developing, or double the probability of recovering from, depression over a six- to 12-month period. In the context of depression, this is a very large impact.

"This was a big effect that we have seen here. It could be that having a stronger social network is an effective way to treat depression. More work needs to be done but it may that we could significantly reduce the burden of depression through cheap, low-risk social interventions," House said.

The findings, which are detailed in the journal Proceedings of The Royal Society B, suggest that promotion of any friendship between adolescents can reduce depression since having depressed friends does not put them at risk, but having healthy friends is both protective and curative.