Life On Mars #4
How to avoid catching depression, the risks of being a sofa enthusiast and yet more rodents
This Christmas edition of Life On Mars looks at how depression may be catching (particularly relevant at this time of year, perhaps, when we’re so far away from summer sunlight), the mental health risks of teenagers whose bottoms are too attached to their sofas and armchairs, and the long-term effects of depriving teenage mice of their beauty sleep.
Depression in families may be catching
Study title: The Temporal Alignment of Mental Health Consultations Across Family Members: A Study of Norwegian Adolescents, Their Parents, and Siblings (December 2024)
Depressed parents are likely have children who struggle with their own mental health: there’s a wealth of research that tells us this. Depression is often assumed to run from the parent to the child, with possible causes that range from parenting (parents who feel low may struggle to meet their children’s needs) through to shared biology. But sometimes links run in the other direction – having a deeply unhappy teenager in the home affects other members of the family. And what about the possibility that depressive feelings are contagious?
This study looked at how depression and other mental health conditions spread through families by assessing administrative and medical records linked to the entire Norwegian teenage population. The research answered a relatively simple question: if depressed teenagers seek help from a healthcare professional, which (if any) of their family members also seek mental health support in the five years leading up to that point and in the five years immediately afterwards? And what do the patterns of support-seeking tell us about how depression emerges in families?
The mental ill-health of family members showed predictably clear links. Parents and siblings of teenagers with depression were twice as likely to seek help for their own mental health during the ten-year study period than the families of unaffected teenagers. But these links don’t seem to be purely driven by biology or a parent managing long-term mental ill-health: in the year that teenagers sought help for depression, their families were most likely to seek help themselves.
Researchers tested whether there might be big life events that could explain the simultaneous onset of depression in families, but controlling for the breakdown of parents’ relationships and the loss of their jobs didn’t change the results. While the study’s authors were clear that we can’t be certain about causality, they said that the ten-year patterns support ‘the idea that an (intensified) mental health problem of a teenager also weakens the parents’ mental health’.
There’s logic to this – if parents are seriously worried about their children, it’s going to take a toll. But there was also a clear link between teenagers’ mental health and that of their siblings, which we might expect to be less affected by care and concern than the parent-child relationship (by somewhere between a small degree and the large degree implied by the stereotypical teenage sibling relationship).
While the authors don’t speak explicitly of contagion apart from in the context of unhealthy lifestyles, they mention a number of things linked to depression that might lead to its spread – more conflict, more need for support from the person feeling low (potentially draining the resources of the person offering it) and changes to usual routines. Other studies have shown that mood is more directly contagious – for example, listening to neutral text spoken in a sad voice can make listeners feel sad themselves.
Takeaways: until protective mind-ware has been invented that prevents us absorbing the negative feelings of those around us, the best way for families to avoid catching depression is to help teenagers through the dark times. Just as mental health dips when teenagers are depressed, so it bounces back when they start to feel better, according to this research.
Last week’s Life On Mars has some brief ideas about how to support teenagers who are feeling low. Parents can also think about keeping conflict to healthy levels (my forthcoming book – did I mention I have a book coming out next month? – has lots of ideas about managing conflict and supporting teenage mental health) and maintaining normal family routines, where possible.
Being glued to the sofa is linked to mental ill-health
Study title: Burdens of Sedentary Behaviour and Symptoms of Mental Health Disorders and Their Associations Among 297,354 School-Going Adolescents from 68 Countries (December 2024)
What’s the point at which teenagers get defined as sedentary or, more directly, what is the point at which they spend too much time sitting on their bums instead of being active? According to the researchers of this study, it’s when they spend at least three hours a day sitting while doing things like watching TV, using devices or talking to friends.
My personal sample may be skewed, because I do not know a single teenager who’d escape being labelled as sedentary with a bar this low. But this study found that 37% of a massive sample – almost 300,000 teenagers in 68 countries – say they spend three or more hours sitting every day. (This sounds astonishingly low when you factor in TV, phones, computer games, reading, calling friends, eating food or catching the bus to school, and it also highlights the problem of asking people how they spend their time rather than actually measuring it. I recently heard my daughter airily respond to someone asking her how much time she spends each day on her phone: ‘Oh, about an hour.’)
Differences between countries may stand up to a bit more scrutiny, as it seems at least possible that teenagers consistently under-report to the same degree regardless of where they live. Teenagers are most likely to be sedentary in the Americas and least likely in South-East Asia. They’re also more likely to be sedentary if they are female.
Researchers found a ‘dose-response’ relationship between sedentary behaviour and mental ill-health. In other words, mental health is worse in teenagers the more time they spend sitting down (with the usual caveats that we can’t be certain which way the causality runs – it may be that teenagers who feel low or anxious are less likely to be active). If sedentary behaviour does cause mental health problems, however, the researchers suggest a few possible mechanisms – exposure to harmful content on technology, less time spent socialising and being physically active, and possible neurobiological changes.
Takeaways: whichever way the causality runs, there’s definitely a link between being sedentary (or, at least, not being active) and poor mental health in teenagers. Girls are more likely to be sedentary. Subtly building in more movement as a family can work better than outright inducements for a sofa-bound teenager, and/or signing them up to a sport they love. (Personal experience suggests it’s not worth getting a dog for them to walk, unless you are prepared for endless arguments about whose turn it is to do so.)
Teenage mice who sleep badly aren’t more vulnerable to depression when they get older
Study title: Disturbing Sleep in Female Adolescent Mice Does Not Increase Vulnerability to Depression Triggers in Later Life (December 2024)
Continuing the rodent theme of the last edition of Life On Mars, this study tested the long-term effects of interrupting the sleep of teenage mice for seven days running (this is a large proportion of your life if you’re a mouse).
The study’s researchers were hoping to demonstrate the vulnerability of the adolescent brain, writing of humans: ‘Adolescence is a crucial neurodevelopmental stage where multiple neuropsychiatric illnesses often emerge, suggesting increased central nervous system vulnerability, specifically at this age, which could be exacerbated by poor sleep.’ Against their expectations, the researchers found that this extended period of poor sleep didn’t increase the mice’s vulnerability to things that might be expected to make them depressed in later life.
Takeaways: if you know or have a teenager who sleeps badly, you could take comfort from these results – but with a large pinch of salt. Humans and mice are not the same, however fetching their sleep masks.
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