Teens bullied in childhood who mistrust others have higher adult mental health risks than those without trust issues

In a recent study published in Nature Mental Health, researchers examined the effect of experiencing bullying in childhood on mental health in adolescence. They found that bullying led to increased mental health problems in late adolescence, partially mediated by the development of interpersonal distrust during middle adolescence, aligning with the predictions of the social safety theory (SST).

Background

The mental health of children and adolescents has become a pressing public health issue, with one in four experiencing significant depression symptoms globally. In the USA, alarming rates of persistent sadness, suicide planning, and attempts among high school students show a concerning upward trend. SST suggests that maintaining social bonds is crucial for human health, while threats like bullying and rejection lead to various health issues. Research indicates that social acceptance promotes well-being, while experiences of rejection engage neural circuits that affect the immune system, potentially leading to long-term mental and physical health challenges.

Peer bullying, a widespread issue globally, significantly affects both physical and mental health in children and adolescents. Previous research indicates causal links between bullying and various mental health challenges, including substance use, anxiety, depression, self-harm, and suicidal behaviors, along with negative academic outcomes such as low achievement and self-esteem. Addressing bullying could involve interventions to eradicate bullying itself, with school-based programs showing reductions of up to 16%, though effectiveness varies. Alternatively, focusing on mitigating the negative effects of bullying could involve understanding pathways linking bullying and mental health, such as through addressing sleep, diet, physical activity, and interpersonal trust, which are often neglected in intervention strategies.

Addressing this need, researchers in the present study tested the predictions of the Social Safety Theory and examined how interpersonal distrust mediated the effects of childhood bullying on mental health difficulties in adolescence. Further, they compared the role of distrust to other potential mediators such as diet, sleep, and physical activity.

About the study

The study used the Millennium Cohort Study’s (MCS) sampling, representing socioeconomically diverse wards and ethnicities across the United Kingdom. Data were collected through interviews of one parent and self-completion questionnaires. The cohort consisted of 10,000 members, primarily singletons or first-born twins or triplets, who provided valid data on self-reported peer bullying at age 11. About 51% of the cohort members were female. Mental health at age 17 was assessed based on experiences of peer bullying at age 11 and levels of interpersonal distrust at age 14.

The frequency of peer bullying was measured by asking cohort members how often other children hurt or picked on them purposefully, with responses ranging from “most days” to “never.” Interpersonal distrust was measured on a scale from 0 to 10, with lower values indicating higher trust and grouped into low (≤3), medium (4–8), and high (≥9) distrust categories based on cutoff values. The primary outcome variable was the total score derived from 20 items in the Strengths and Difficulties Questionnaire (SDQ) completed by cohort members at age 17, assessing emotional, peer, conduct, and hyperactivity/attentional problems. The total score ranged from 1 to 40, with good internal reliability, and was further categorized into internalizing (INT) and externalizing (EXT) problems.

Along with interpersonal distrust, the other mediators considered were diet (primarily fruit eating), sleep (evening chronotype), and physical activity. Control variables included sex, ethnicity, socioeconomic characteristics, body mass index, neighborhood ecology, maternal mental health, vocabulary ability, prior mental health difficulties, and area air pollution levels, all known to be associated with adolescent mental health outcomes. Analyses involved correlation analysis, as well as structural equation models with multiple imputations to handle missing data.

Results and discussion

The study revealed associations between peer bullying, interpersonal distrust, chronotype, dietary habits, and total, INT, and EXT mental health difficulties. Bullying at age 11 was linked to increased mental health issues at age 17, with both direct and indirect effects mediated through interpersonal distrust. Interpersonal distrust showed the strongest indirect association with mental health difficulties. Moreover, the link between interpersonal distrust and mental health problems was stronger than that between bullying and total mental health problems. Notably, males experienced fewer emotional and peer problems than females.

The study’s limitations include the lack of detailed temporal information, reliance on self-reported mental health assessments, lack of inference on causality, and simplified measures of peer bullying and interpersonal trust. Further research is needed to explore biological processes, such as oxytocin dysregulation, linking peer bullying, distrust, and mental health in the youth.

Conclusion

In conclusion, the findings reveal that interpersonal distrust significantly contributes to mental health difficulties in adolescence and mediates the link between childhood bullying and later mental health problems. They highlight the importance of addressing trust issues in interventions for bullying, providing crucial insights into mitigating socio-emotional problems among adolescents.