Can misery be contagious? There is no doubt that the number of Britons complaining of low mood and depression-like symptoms such as sadness and a feeling of helplessness is rising sharply.
The latest figures from the Office for National Statistics survey show that one in six people are experiencing moderate or severe depressive symptoms, up 60 per cent from the previous three years.
This dramatic rise has been variously attributed to the increasing mental pressures caused by Covid-19 lockdowns and the subsequent cost of living crisis.
But could the skyrocketing rate of depression have another cause? Could it be contagious, something you can “catch,” like a cold or flu?
This is the idea suggested by psychologists in Finland, writing in the prestigious journal JAMA Psychiatry.
The number of Britons complaining of low mood and depression-like symptoms such as sadness and feeling helpless is rising sharply.
The latest survey figures from the Office for National Statistics show that one in six report moderate or severe depressive symptoms.
The team, led by Christian Hakulinen, an associate professor of psychology at the University of Helsinki, tracked the health records of more than 700,000 children for 11 years, starting at age 16.
Their analysis found that if one student in a class developed obvious signs of depression, there was at least a 9 percent greater chance that his or her peers would develop it, too.
Those who had more than one affected classmate had at least an 18 percent higher risk of being diagnosed during the 11-year study.
Even when the numbers were adjusted to account for factors that could have an impact, such as income level, the association between a depressed student and increased depression among classmates remained.
What’s more, although the strength of the influence diminished over time, it persisted up to 11 years after the students left school.
Previous studies have also suggested that depression may be contagious.
For example, a 2014 US study published in the journal Clinical Psychological Science found that depressive thoughts can spread among college roommates. Psychologists at the University of Notre Dame in Indiana studied 108 new students who had been randomly assigned to roommates in pairs.
Students answered an online survey about their thinking styles, stress exposure and mood during the first month and then again three and six months later. In particular, the researchers studied a type of thinking linked to depression, called rumination, which involves thinking things over in their heads.
Researchers found that if one roommate had begun his or her college days habitually ruminating, their previously non-ruminating roommate tended to pick up the habit. They also had more than twice as many depressive symptoms as the non-ruminating students.
Dr. Jack Andrews, a developmental psychologist at Oxford University, says that “depression can spread through co-rumination.”
As Dr. Jack Andrews, a developmental psychologist at the University of Oxford who researches this phenomenon called social contagion, explains: “Depression may actually spread through co-rumination, sharing the process of repeatedly locking yourself into negative thought processes and catastrophizing, without finding a solution.”
But it’s not just students who are prone to this, as Dr Andrews told Good Health: “Scientists have found evidence of this on social networking sites, where relationships between individuals can be mapped; they show that mood spreads among adults too.”
He points to further evidence of emotional contagion from the Framingham Study, which has collected medical information on those living in Framingham, Massachusetts, since 1948.
“The researchers collected information about depressive symptoms, such as low mood and hopelessness, and asked people to name their close friends and family,” says Dr. Andrews.
‘In 2012, researchers mapped the city’s social network—to track which people spent time together—and then examined whether levels of depressive symptoms among friends were related.’
In a paper published in the journal Molecular Psychiatry in 2010, psychiatrists at Harvard Medical School showed that Framingham residents were more likely to have depressive symptoms if a close friend also had them.
Dr Andrews adds: “This was true even for three degrees of separation: having a depressed friend of a friend of a friend also increases the odds of suffering from depression.”
And it wasn’t just low mood that was seen among friends: the same pattern was found for happiness levels.
Scientists are still debating the mechanisms through which depression might be contagious.
Last year, Dr Andrews and his colleagues published their theory of “prevalence inflation,” suggesting that increased discussion in society and on social media about mental health issues could lead to more people believing they have mental illness.
“This may mean that more people identify genuine symptoms and seek help,” she says. “But it may also mean that people mistake normal, low mood for depression, and believe they are ill when they are not. This hypothesis needs to be tested.”
Additionally, Dr Andrews says there may also be an element of depression that is perceived as “cool” among some groups.
“Studies on groups of ‘outsider’ youth, such as the Goths, show that their members align their behaviour as a way of consolidating their belonging to the group,” he explains.
‘In this way, individuals can adjust their moods to intensify their sense of belonging to a group. This happens especially in adolescents.’
Christian Hakulinen, associate professor of psychology at the University of Helsinki in Finland
There are other theories on this. In 2022, researchers in Brazil suggested that we are programmed to pick up on depressive emotions in others through specialized brain cells called mirror neurons.
Brain scanning studies have shown that when a person watches another person perform actions such as sawing wood or dancing, their mirror neurons activate and “rehearse” the rest of their brain to perform the task in a similar way.
In an article published in the journal Neuroscience & Biobehavioral Reviews, Brazilian researchers claimed that humans mirror the emotions of others in a similar way.
Other research suggests that we might even catch depression through our sense of smell — that is, we can smell it off each other.
Scientists have already established that other emotions (fear and disgust) can be contagious in this same way.
In 2012, psychologists at Utrecht University exposed women to swabs containing sweat from men who had just watched a scary or disgusting movie clip.
The women were asked to complete a computer task while unwittingly smelling the men’s sweat, and researchers recorded their facial expressions.
In the journal Psychological Science, researchers reported how women exposed to the sweat of men in the scared group were more likely to widen their eyes in a fearful expression, while those who smelled the sweat of the disgusted group were more likely to scrunch up their faces in revulsion.
The idea that pheromones (chemical signals that humans and animals emit to communicate with each other) could spread depressive states comes from preliminary research published on the scientific website Research Square.
Last year, scientists at the Fourth Military Medical University in China reported that they found that depressed laboratory mice emit a pheromone in their urine called major urinary protein 1, which causes other mice to become wary and unsociable when they smell it.
Researchers say humans have a similar pheromone, human progestogen-associated endometrial protein (hPAEP), which may be linked to unsociable behavior in people.
It should be noted that this is preliminary research that has not been independently reviewed by experts.
But however depressive feelings spread, we need to strive to build resilience against them, says Professor Vivian Hill, director of professional development in educational psychology at the UCL Institute of Education.
Commenting on the latest Finnish research, he says: “There seems to be a leech effect in groups, where emotions can spread.”
She would like to see mental health topics and coping strategies included in school curricula.
Adults also need to develop resilience, she says. “If you find a particular experience challenging, ask yourself: How can I cope with it in a more positive way?”
‘The answer may be going to the gym or talking to positive friends. Just as we need to exercise and eat healthily for our bodies, we also need to do healthy things for our minds.’
Eat more…
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Suggested mechanisms include anti-inflammatory action and compounds that influence fat burning and storage processes.
Ginger may help you lose weight, according to a study published in the journal Nutrition Reviews
