London, Sep 21 (IANS): While your friend's bad or good mood can affect you, it is unlikely to increase your risk of falling into depression, researchers have found.

The findings showed that mood does spread over friendship networks, as do various different symptoms of depression such as helplessness and loss of interest.

Having more friends who suffer worse moods is associated with a higher probability of an individual experiencing low moods and a decreased probability of improving.

However, the effect from lower or worse mood friends is not strong enough to push the other friends into depression.

Understanding how changes in the mood get affected by friends' mood would help the researchers to develop interventions that tackle adolescent depression, said Rob Eyre, Public Health Statistics Researcher at Britain's University of Warwick.

Previous studies have found social support and befriending to be beneficial to mood disorders in adolescents while the recent experiments suggest that an individual's emotional state can be affected by exposure to the emotional expressions of social contacts.

The new study, published in the journal Royal Society Open Science, also found that components of mood particularly appetite, tiredness and sleep may spread from person to person via a process known as social contagion.

According to the World Health Organisation (WHO), an estimated 350 million people across the world suffer from depression, which impacts an individual's abilities to work and socialise and at worse leads to suicide.

"Understanding that these components of mood can spread socially suggests that while the primary target of social interventions should be to increase friendships because of its benefits in reducing the risk of depression, a secondary aim could be to reduce spreading of negative mood," said co-author Frances Griffiths, Professor at the varsity.