Depression does not spread: Study

Be rest assured that simply talking to or helping a friend who is suffering from depression would not affect your own mental health as depression does not spread from friend to friend, new research suggests.

While depression does not 'spread', having enough friends with a healthy mood can halve the probability of developing, or double the probability of recovering from, depression over a six to 12 month period, the findings showed.

"Our results 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," said study lead author Edward Hill from University of Warwick in England.

The findings are the result of a study of the way over 2,000 teenagers in a group of US high schools influenced each others' mood.

The researchers used a mathematical model to establish if depression spreads from friend to friend.

Adolescents who have five or more mentally healthy friends have half the probability of becoming depressed compared to adolescents with no healthy friends, the researchers determined with the help of their mathematical model.

And teenagers who have 10 healthy friends have double the probability of recovering from depressive symptoms compared to adolescents with just three healthy friends.

"Depression is a major public health concern worldwide. But the good news is we have found that a healthy mood amongst friends is linked with a significantly reduced risk of developing and increased chance of recovering from depression," Frances Griffiths, professor at Warwick Medical School, University of Warwick in England, noted.

"Our results offer implications for improving adolescent mood. In particular they suggest the hypothesis that encouraging friendship networks between adolescents could reduce both the incidence and prevalence of depression among teenagers," Griffiths said.

The study was published in the journal Proceedings of the Royal Society B.