Mental Disorders in Teens May Spread Through Peer Networks

A recent study reveals that adolescents are at a higher risk of developing mental disorders if they have classmates with such diagnoses, suggesting that peer influence plays a significant role in the transmission of mental health issues.

A new study has found that adolescents with classmates diagnosed with mental disorders are at an increased risk of developing similar issues.

The research, published in the journal JAMA Psychiatry on May 22, analyzed data from 713,809 Finnish citizens born between 1985 and 1997.

The participants were monitored from the ninth grade (approximately age 16), until they were diagnosed with a mental disorder, emigrated, died, or the study concluded in 2019.

The findings reveal a significant “dose-response” relationship: the more classmates diagnosed with mental disorders, the higher the risk for other students.

Specifically, having more than one diagnosed classmate increased the risk by 5%, with the highest risk observed during the first year after exposure.

The Scope of Mental Disorders

The study examined a wide range of mental disorders, including mood disorders, anxiety disorders, eating disorders, and behavioral and emotional disorders.

Among these, mood, anxiety, and eating disorders showed the highest risks associated with peer influence.

For instance, the presence of one classmate diagnosed with one of these disorders resulted in a 9% increased risk during the first year, escalating to 18% if more than one classmate was diagnosed.

Even after the first year, the risk remained elevated, indicating a lasting impact of peer networks on mental health.

Mechanisms of Transmission

Several mechanisms could explain the transmission of mental disorders among adolescents.

One plausible explanation is the normalization of mental health issues within peer groups.

When individuals are exposed to peers with diagnosed mental disorders, it may increase awareness and openness about mental health, leading to a higher likelihood of seeking help and receiving diagnoses.

Another mechanism could be direct interpersonal contagion.

Adolescents are highly susceptible to social influence, and prolonged exposure to peers with mental health issues might lead to similar symptoms in others through emotional contagion.

For example, long-term exposure to a depressive individual could lead to the development of depressive symptoms in others due to well-established neural mechanisms of emotional contagion.

Likewise, social learning theory suggests that adolescents might imitate the behaviors and attitudes of their peers, including maladaptive coping strategies associated with mental disorders.

This imitation could contribute to the spread of mental health issues within peer networks.

Implications for Public Health and Education

The study’s findings have significant implications for public health and educational policies.

Interventions that promote mental health awareness and provide resources for early detection and treatment of mental disorders could mitigate the risks identified in the study.

And policies that address broader social determinants of health, such as family and community support systems, are vital.

The study suggests that addressing mental health at a community level, rather than just focusing on individuals, could have far-reaching benefits.

Schools could implement programs that foster a supportive and inclusive environment, encouraging students to seek help and support one another.

Conclusion and Future Research

This study is the largest and most comprehensive investigation on the transmission of mental disorders within adolescent peer networks to date.

The results suggest a dose-response association between the number of classmates diagnosed with mental disorders and the later risk of developing a mental disorder.

The risk is particularly high for mood, anxiety, and eating disorders.

Further research is still needed to clarify the mechanisms behind these observed associations and to explore effective strategies for mitigating the spread of mental health issues among adolescents.

The findings highlight the importance of considering peer influence when developing prevention and intervention measures for adolescent mental health.

Addressing the potential transmission of mental disorders within peer networks could substantially reduce the burden of mental health issues in society.

“Mental disorders might be socially transmitted within adolescent peer networks,” the authors write, “and prevention and intervention measures that consider potential peer influences on early-life mental health could substantially reduce the disease burden of mental disorders in society.”

Study Details

  • Title: “Transmission of Mental Disorders in Adolescent Peer Networks”
  • Authors: Jussi Alho; Mai Gutvilig; Ripsa Niemi; Kaisla Komulainen; Petri Böckerman; Roger T. Webb; Marko Elovainio; Christian Hakulinen.
  • Publication Date: May 22, 2024
  • Journal: JAMA Psychiatry
  • DOI: 10.1001/jamapsychiatry.2024.1126