The study, published in the journal Nature Mental Health, is believed to be the first to examine the link between peer bullying, interpersonal distrust, and the subsequent development of mental health problems, such as anxiety, depression, hyperactivity and anger.

For the study, researchers at the University of California-Los Angeles (UCLA) in the US and the University of Glasgow in the UK used data from 10,000 children in the UK.

They found that adolescents who were bullied at age 11 and in turn developed greater interpersonal distrust by age 14 were around 3.5 times more likely to experience clinically significant mental health problems at age 17 compared to those who developed less distrust.

The findings could help schools and other institutions to develop new evidence-based interventions to counter the negative mental health impacts of bullying, said Dr. George Slavich, who directs UCLA Health’s Laboratory for Stress Assessment and Research.

“There are few public health topics more important than youth mental health right now,” Slavich said.

“In order to help teenagers reach their fullest potential, we need to invest in research that identifies risk factors for poor health and that translates this knowledge into prevention programmes that can improve lifelong health and resilience,” he said.

Prior research has identified associations between bullying and mental and behavioural health issues among youth, including its impact on substance abuse, depression, anxiety, self-harm and suicidal thoughts.

However, following youth over time, this study is the first to confirm the suspected pathway of how bullying leads to distrust and, in turn, mental health problems in late adolescence.

Slavich said when people develop clinically significant mental health problems during the teenage years, it can increase their risk of experiencing both mental and physical health issues across the entire lifespan if left unaddressed.

In addition to interpersonal distrust, the team examined if diet, sleep or physical activity also linked peer bullying with subsequent mental health problems.

However, only interpersonal distrust was found to relate bullying to greater risk of experiencing mental health problems at age 17.

“What these data suggest is that we really need school-based programmes that help foster a sense of interpersonal trust at the level of the classroom and school,” Slavich said.

“One way to do that would be to develop evidence-based programmes that are especially focused on the transition to high school and college, and that frame school as an opportunity to develop close, long-lasting relationships,” he said.