Theravive Home

A new European study recently published in the Journal of Molecular Psychiatry is the first to show that chronic peer victimization, otherwise known as bullying, during adolescence, changes the brain structure of teens, making them more susceptible to developing anxiety. The findings are part of the IMAGEN project, a longitudinal study using magnetic resonance imaging (MRI) to examine links between mental health and adolescent brain development. 

“The IMAGEN project was the first imaging-genetics research project following school-recruited adolescents over time,” study author and London, England-based, IMAGEN Project Coordinator, Erin Burke Quinlan told us. “In this particular study, we wanted to see if we could identify if peer victimization, an umbrella term related to bullying, affects mental health via the brain. It seems intuitive that this should be the case but it hadn’t yet been shown from what we could tell.”

According to stopbullying.gov, an official website of the United States government, 28 per cent of students experience bullying in grades six to twelve while 30 per cent have admitted to having bullied others. Seventy per cent of U.S. students and school staff say they have witnessed bullying at school. 

“Peer victimization, especially if it is chronic and persisting, can have long-term effects on physical and mental health,” Burke Quinlan told us. “It is related to a range of mental disorders such as anxiety and depression. We wanted to see if this relationship has a basis in the brain.”

Bullying can be stopped within ten seconds almost 60 per cent of the time when someone who witnesses it decides to step in and do something about it. When it comes to cyberbullying, 15 per cent of students in grades nine to twelve in the U.S. say they’ve experienced it and over 55 per cent of LGBTQ students say cyberbullying has affected them.

“First, we identified a group of adolescents who experienced chronic peer victimization at ages 14, 16, and 19 using their answers on a self-report bullying questionnaire,” Burke Quinlan told us. “We then checked whether they had higher symptoms of common mental disorders such as anxiety and depression. Finally, we used adolescents’ MRI scans from ages 14 and 19 to see if changes in the volume of particular brain areas differed between the two groups.”

Social and verbal bullying happen most often compared to cyber and physical bullying. The most common form of bullying is name calling which is experienced by 44 per cent of students. Forty-three per cent of students say they've experienced teasing and 36 per cent say they have been victims to rumors or lies being told about them.

“We first confirmed what had been shown previously, that peer victimization relates to an increase in mental disorders such as anxiety and depression,” Burke Quinlan told us. “The novel finding was that this relationship was due, in part, to exaggerated decreases in the volume of particular brain structures from ages 14 to 19.” 

Most students experience bullying right in their own classrooms as well an in school hallways. The next most common place at school where students experience bullying is in the cafeteria and the gym, followed by the bathroom. Adults are told about bullying by students only 20 to 30 per cent of the time.

“We were not surprised by the sharper decreases in brain volume but we were somewhat surprised by the brain regions showing this decline,” Burke Quinlan explained to us. “Although these structures, the caudate and putamen, were included in our study as they've been shown to be affected by stress, we thought that other areas more ‘classically’ related to things like emotion and memory would be the frontrunners. However, the caudate and putamen are important for learning and for how we execute our behaviors so they could help how we develop anxiety-like responses and behaviors to stressful situations.”

Anxiety is the most common adolescent mental health disorder affecting one in three adolescents in the U.S. by the time they reach 18 years of age. Females are twice as likely as males to experience depression during adolescence and the rate of anxiety in teenagers has increased by nearly 40 per cent over a four year period from 2005 to 2014.

“I think our findings are important to show that peer victimization's impact is biologically significant,” Burke Quinlan told us. “I’d hope findings from studies such as ours could eventually inform policies to reduce, or even prevent bullying and give youths the tools to deal with it, ultimately preventing the brain changes associated with the development of anxiety.”

Burke Quinlan also explained that it's important to note that the brain changes aren't ‘damage’ per se, it's just that those victimized show an altered pattern of development.

“Furthermore, we can't speak to whether these changes are reversible, as we would need to follow the adolescents well into adulthood,” Burke Quinlan told us. “This is why prevention and early identification of bullying is so important. It's likely easier to overcome the hurdle of managing bullying earlier than changes to the brain later.”