A bad mood may be contagious, but depression is not
If you’ve never personally experienced depression, it can be easy to dismiss the illness as just a matter of having a “bad mood.” I mean, we’ve all felt “down” or “woke up on the wrong side of the bed”, so why would it be that much harder to just stop being depressed?
The answer, of course, is that depression isn’t a simple matter of mood. It is a legitimate health issue that stems from a combination of biochemistry, environment, and genetics. To help prove this, a team of scientists recently showed that normal moods are contagious, or can be easily passed to friends or others around you. Depression, on the other hand, is not something that can be passed on to others.
For the study, researchers from the University of Warwick tracked how a single person’s mood can spread across friendship networks using data from the National Longitudinal Study of Adolescent to Adult Health. This set of data includes information about the moods and friendship networks of American adolescents in school.
As the report published in the journal Royal Society Open Science explains, mood effectively spreads throughout friendship networks. The effect is so strong, it can even lead to some symptoms of depression like feelings of helplessness or loss of interest to affect members of the friend network. However, this phenomenon is not strong enough to actually push others into prolonged clinical depression.
The mathematical model they developed for the study shows that having more friends who experience poor moods is linked to a higher probability of experiencing similarly low moods, but the effect also works in the opposite way. Those with a higher number of optimistic or positive-minded people in their social circle were more likely to experience better moods.
As lead author of the study and public health statistics researcher Rob Eyre explains:
“We investigated whether there is evidence for the individual components of mood (such as appetite, tiredness, and sleep) spreading through US adolescent friendship networks while adjusting for confounding by modeling the transition probabilities of changing mood state over time.
“Evidence suggests mood may spread from person to person via a process known as social contagion.
“Previous studies have found social support and befriending to be beneficial to mood disorders in adolescents while recent experiments suggest that an individual’s emotional state can be affected by exposure to the emotional expressions of social contacts.
“Clearly, a greater understanding of how changes in the mood of adolescents are affected by the mood of their friends would be beneficial in informing interventions tackling adolescent depression.”
The findings also show that typical methods for improving an individual’s mood, such as exercising or sleeping well, can also have positive effects on the moods of a friend circle. However, the same cannot be said for friend-circles including a person with depression.