A recent study conducted by researchers from the University of Helsinki, the Finnish Institute for Health and Welfare, the University of Jyväskylä, and the University of Manchester explored whether mental disorders can be transmitted within social networks formed by school classes. This study, the largest and most comprehensive of its kind, involved over 700,000 ninth-grade pupils from 860 Finnish schools. The adolescents were followed for a median of 11 years after ninth grade. The researchers found that the number of classmates diagnosed with a mental disorder was linked to a higher risk of receiving a mental disorder diagnosis later in life, especially in cases of mood, anxiety, and eating disorders.
Previous studies have indicated that depressive symptoms may be transmitted from one individual to another in social networks. However, these studies often allowed research subjects to choose their social networks independently, potentially introducing bias into the data. By focusing on school classes, where individuals do not have the ability to choose their classmates, the researchers were able to eliminate this bias and conduct a more accurate assessment of the spread of mental disorders within social networks. The use of comprehensive Finnish registers enabled the researchers to define social networks and follow adolescents over an extended period of time to better understand the development and impact of mental health problems.
While the study revealed a strong association between classmates with mental disorders and an increased risk of receiving a mental disorder diagnosis later in life, the researchers caution that this does not necessarily imply a direct causal relationship. Additionally, the study did not explore how mental disorders are transmitted between individuals within social networks. It is possible, for example, that having peers who have sought help for mental health issues may lower the threshold for seeking help oneself, potentially leading to a positive normalization of diagnosis and treatment of mental disorders within social networks.
Mental disorders are a significant global challenge that affects individuals, society, and the economy. The prevalence of anxiety and mood symptoms, especially among young people, has been increasing in recent years. Studies have shown that approximately half of all cases of mental disorder onset in adulthood occur during adolescence. As a result, preventive measures and early intervention are crucial in addressing mental health issues. The findings of this study suggest that mental disorders can spread from one adolescent to another within social networks, highlighting the importance of considering this factor when designing preventive strategies.
The study involved over 700,000 Finnish citizens born between 1985 and 1997 and followed them from the end of comprehensive school until they received their first mental disorder diagnosis, relocated from the country, or died. The median follow-up period was 11.4 years, with the study concluding at the end of 2019. The research was funded by the European Research Council (ERC) and the Research Council of Finland. By shedding light on the transmission of mental disorders within social networks, this study provides valuable insights into how mental health problems develop and affect individuals within social settings, emphasizing the importance of preventive measures and early intervention in addressing these issues.