Could misery be contagious? There’s no doubt that the number of Britons complaining of low mood and depression-like symptoms, such as sadness and feeling helpless, is spiralling.
The latest survey figures from the Office for National Statistics show one in six report moderate or severe depressive symptoms. This is 60 per cent higher than the previous three years.
This towering rise has been blamed variously on mounting mental pressures caused by the Covid-19 lockdowns and the subsequent cost-of-living crisis.
But could snowballing rates of depression have another cause? Could depression be contagious — something that you can ‘catch’, much like a cold or flu?
That is the idea being suggested by psychologists in Finland, writing in the highly reputed journal JAMA Psychiatry.
The number of Britons complaining of low mood and depression-like symptoms, such as sadness and feeling helpless, is spiralling
The latest survey figures from the Office for National Statistics show 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, from age 16.
Their analysis found that if one student in a class developed obvious signs of depression, there was at least a 9 per cent higher chance that their classmates would also develop it.
Those with more than one affected classmate had at least an 18 per cent higher risk of being diagnosed themselves during the 11-year study.
Even when figures 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, while the strength of the influence declined over time, it still persisted for up to 11 years after the students had left school.
Previous studies have also suggested that depression might be contagious.
For example, a 2014 U.S. study in the journal Clinical Psychological Science found depressive thinking may spread between roommates at university. Psychologists at the University of Notre Dame, Indiana, studied 108 new students who’d been randomly assigned to share rooms as pairs.
The students took an online survey about their thinking styles, stress exposure and mood within their first month, and then again three and six months later. In particular, the investigators studied a type of thinking linked with depression, called rumination, which involves brooding about things.
The researchers found that if one roommate had started their university days ruminating habitually, then their previously rumination-free roommate would often pick up this habit. They also had more than double the number of depressive symptoms of students who didn’t ruminate.
Dr Jack Andrews, a developmental psychologist at Oxford University, says ‘depression may indeed spread through co-rumination’
As Dr Jack Andrews, a developmental psychologist at Oxford University, who is researching this so-called social contagion phenomenon, explains: ‘Depression may indeed spread through co-rumination — sharing the process of repeatedly locking into negative thought processes and catastrophising, without coming up with a solution.’
Nor is it just students who are prone to this, as Dr Andrews told Good Health: ‘Scientists have found evidence of this from social networking sites, where you can map the relationships between individuals — 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 about those living in Framingham, Massachusetts, since 1948.
‘The researchers collected information on depressive symptoms, such as low mood and hopelessness — and asked individuals to name their close friends and family,’ says Dr Andrews.
‘In 2012, the researchers mapped the social network of the town — to track which people spent time together — and then examined whether levels of depressive symptoms among friends were linked.’
Writing in the journal Molecular Psychiatry in 2010, psychiatrists from Harvard Medical School showed that Framingham residents were more likely to have depressive symptoms if a close friend did, too.
Dr Andrews adds: ‘This was even true for three degrees of separation — having a depressed friend of a friend of a friend also increasing one’s chance of depression.’
And it wasn’t just low mood that clustered among friends: the same pattern was found for levels of happiness.
Scientists are still arguing about the mechanisms via which depression might be contagious.
Last year, Dr Andrews and colleagues published their ‘prevalence inflation‘ theory, suggesting that increased discussion in society and on social media of mental health problems could be leading to more people believing they have mental illnesses.
‘This can mean more people identifying real symptoms and seeking help,’ he says. ‘But also it may mean that people mistakenly identify normal, everyday low mood as depression — and believing that they are ill when they aren’t. This hypothesis needs testing.’
Furthermore, Dr Andrews says there may also be an element of depression being perceived as ‘cool’ among some groups.
‘Studies of ‘outsider’ youth groups, such as Goths, show that members align their behaviours as a way of cementing group-belonging,’ he explains.
‘In this way, individuals may align their moods in order to intensify their sense of group-belonging. This happens particularly in adolescents.’
Christian Hakulinen, an associate professor of psychology at the University of Helsinki in Finland
Other theories abound. In 2022, researchers in Brazil suggested that we are wired to pick up depressive emotions from each other through specialised brain cells called mirror neurons.
Brain-scanning studies have shown how when one person watches another perform acts such as sawing wood or dancing, their mirror neurons activate and ‘rehearse’ the rest of their brain to perform the task in similar fashion.
Writing in the journal Neuroscience & Biobehavioral Reviews, the Brazilian researchers said that humans mirror each other’s emotions in a similar way.
Other research suggests that we might even be able to catch depression from each other through our sense of smell — i.e. that we sniff it on each other.
Scientists have already established other emotions — fear and disgust — may be contagious in just this way.
In 2012, psychologists from Utrecht University exposed women to swabs containing the sweat of men who had just watched either a scary or a disgusting film clip.
The women were asked to complete a computer task while they unknowingly sniffed the men’s sweat, and the researchers recorded their facial expressions.
In the journal Psychological Science, the investigators reported how the women exposed to the sweat of the men in the scared group were more likely to open their eyes in a fearful expression, while those who sniffed the sweat of the disgust group were more likely to scrunch their faces in repulsion.
The idea that pheromones — chemical signals that humans and animals emit to communicate with each other — might spread depressive moods comes from preliminary research on the scientific website Research Square.
Scientists at Fourth Military Medical University in China reported last year how they found that depressed lab mice emit a pheromone in their urine called Major urinary protein 1 that causes other mice to become wary and stop being sociable when they sniff it.
The researchers claim that humans have a similar pheromone, human progestagen-associated endometrial protein (hPAEP), that may be linked to unsociable behaviour in people.
It must be stressed that this is preliminary research that has not been independently scrutinised by experts.
But regardless of how depressive feelings spread, we should strive to build resilience against it, says Professor Vivian Hill, director of professional educational-psychology training at the UCL Institute of Education.
Commenting on the latest Finnish research, she says: ‘It does seem that there is a leeching effect in groups, where emotions can spread.’
She would like mental health and coping strategies on schools’ curriculums.
Adults, too, need to build resilience, she says. ‘If you find a particular experience challenging, then ask yourself, how do I approach it more positively?’
‘Your answer may lie in going to the gym or having conversations with positive friends. Just as we need to exercise and eat healthily for our bodies, we need to do healthy things for our minds.’
Eat more…
Ginger: It could help with weight loss, according to a study in the journal Nutrition Reviews, which analysed the results of 27 previous trials into the effects of ginger on weight and found that consuming 2g a day for at least eight weeks led to significant loss.
Mechanisms which have been suggested include anti-inflammatory action and compounds that influence processes to burn and store fat.
Ginger could help with weight loss, according to a study in the journal Nutrition Reviews