How being bullied ups mental illness risk in teens?

Being bullied can change the physical structure of the adolescent brain, increasing the risk of mental illness, a study has found. Researchers from King's College London in the UK suggest that the effects of constantly being bullied are more than just psychological.

The study, published in Molecular Psychiatry, is the first to suggest that chronic peer victimisation during adolescence impacts mental health via structural brain changes. Researchers analysed data, questionnaires and brain scans of 682 participants from England, Ireland, France and Germany.

As part of this project, high resolution brain scans of participants were taken when they were 14 and 19 years old. At the ages of 14, 16 and 19 these participants also had to complete questionnaires about whether they had been bullied, and to what extent.

Overall, the results showed that 36 of the 682 young people were found to have experienced chronic bullying. The data of these participants were compared with those of the others who had experienced less chronic/severe bullying.

Changes in brain volume as well as the levels of depression, anxiety and hyperactivity at age 19 were taken into account. The subsequent findings validate and extend the literature linking peer victimisation with mental health problems.

However, the novel finding is that bullying is linked to decreases in the volume of parts of the brain called the caudate and putamen. These changes were found to partly explain the relationship between high peer victimisation and higher levels of general anxiety at age 19.

"Although not classically considered relevant to anxiety, the importance of structural changes in the putamen and caudate to the development of anxiety most likely lies in their contribution to related behaviours such as reward sensitivity, motivation, conditioning, attention, and emotional processing," said Erin Burke Quinlan, lead researcher of the study.