During adolescence, young people become especially sensitive to peer influence – more so than any other time in life.
So, how does this affect their mental health?
A new study from Finland, released today, analysed data from more than 600,000 young people born between 1985 and 2000 (meaning both millennials and early Gen Zs).
It found that people whose peers had been diagnosed with a mental health condition – such as anxiety or depression – were more likely to develop a mental health condition themselves.
The researchers say these findings support the idea of “social transmission” of mental health conditions. But we need to be careful: this doesn’t mean these conditions are “contagious” in the same way as an infectious disease.
Many other factors, including genetic predisposition, also play a role in teen mental health. The data also can’t tell us if the “peers” are actually friends. Let’s take a look.
Mental health conditions on the rise
Around the world, depression and anxiety are increasing among young people. In Australia, recent data shows rates of anxiety in young people have increased from 13% to 28% over the past 15 years, while suicide attempts have doubled.
Despite greater awareness and expanded mental health services, young people are experiencing more severe and complex mental health challenges than ever before.
We know both friends and family play an important role in mental health. Family factors – including genetics – and environmental influences – such as peer relationships – each uniquely shape the development of mental health conditions.
What the study did and what it found
The new Finnish study explored the relationship between young people’s mental health and that of their peers. It aimed to find out whether having a peer with a diagnosed mental health condition, or a peer with a family history of one, increases your own likelihood of a diagnosis.
The researchers did this by analysing nationwide data in Finland, including health records and school enrolments.
The study made some interesting key findings:
if you had a peer with a diagnosed mental health condition or a peer with diagnoses in their family – for example, anxiety – you were more likely to be diagnosed with this same condition
the effect was stronger among peers who attended the same school, rather than lived in the same area – particularly in later adolescence.
The authors conclude that the findings support the idea of “transmission” of mental health risk in adolescence.
But there are some important caveats
It’s important to note that terms like “transmission” or “contagion” are not used in the same way as for infectious diseases. You cannot “catch” a mental health condition.
Instead, these terms describe how emotions, behaviours and social norms can spread between peers over time and influence mental health. For example, if there is increased awareness of mental health and reduced stigma within a group of peers, people in that group may be more comfortable seeking help (although the study didn’t test this).
Importantly, peer relationships and genetic risk are part of a complex mix of factors that shape adolescent mental health.
Because this study defined peers by school year or location, findings likely reflect shared school and community influences. In other words, these “peers” were likely exposed to similar environmental conditions, ranging from school cultures and educational approaches to neighbourhood features such as green space.
What the study couldn’t measure
The size of this study is a key strength. However, because this is achieved by using “register data” such as health records, there are some constraints:
the data can’t tell you if people actually knew each other or were friends. So the study defined “peer networks” according to school (for example, those in the same grade and born in the same year) or where they lived (for example, people in the same postcode born in the same year)
“genetic risk” was inferred from family diagnoses, rather than DNA, and there may be various reasons someone with a mental health condition doesn’t get a diagnosis
the study couldn’t account for all the factors known to increase or lower someone’s risk of having a mental health condition. For example, it included someone’s sex, age and their parents’ income and education level. But it didn’t consider other factors known to play a role in adolescent mental health, such as their gender identity, ethnicity and what their school is like, as well as lifestyle behaviours, such as whether they smoke, drink alcohol or get regular exercise
the study also found that if someone’s peer had a family history of a mental health condition, such as a substance use disorder, they had a higher chance of receiving the same diagnosis. But because the data only looks at diagnosis, it can’t capture other factors which might better explain the link – such as shared factors in families’ social environments.
Where to next?
This study shows both peers and their family risk are linked to adolescent mental health, but it cannot explain how these effects occur.
To understand how mental health conditions “spread” within peer networks, we still need research that disentangles the effects of peer selection (choosing similar friends) from peer influence (how friends shape each other).
But the importance of school environments is clear. School-based mental health programs which harness the influential role of peers are key. In Australia, a program called Mind your Mate, has already shown promise in lowering depression risk in teens through education about mental health and how to support peers.
Together, these findings point beyond individuals to the wider environments young people are part of. Ultimately, improving adolescent mental health means investing in the people and places around them, such as the schools and communities where peer relationships take shape.
Thank you to Professor Cath Chapman for her role in developing this article.
If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14. Aboriginal and Torres Strait Islander people can also call 13YARN on 13 92 76.
Scarlett Smout, Research Fellow, The Matilda Centre for Research in Mental Health and Substance Use, University of Sydney; Louise Birrell, Researcher, The Matilda Centre for Research in Mental Health and Substance Use, University of Sydney, and Tim Slade, Professor, The Matilda Centre for Research in Mental Health and Substance Use, University of Sydney
This article is republished from The Conversation under a Creative Commons license. Read the original article.
