Our recent paper (Singham et al., 2017, JAMA Psychiatry) investigates the unique contribution of childhood peer victimisation to mental health outcomes, and examines if these effects are sustained over a 2-year and 5-year period from the time of exposure to bullying. Using the MZ twin differences design, there was strong evidence for concurrent direct effects of childhood exposure to peer victimisation on anxiety and depression, across multiple informants and scales. Effects on anxiety persisted over 2 years, but were not sustained after 5 years. Long-term (5-year) enduring effects were observed for paranoid thoughts and cognitive disorganisation. A key finding was that while phenotypic associations were consistently found to be significant, most of these relationships were not significant in the MZ analysis, when controlling for all genetic and shared environmental influences. This suggests that associations between exposure to bullying and mental health difficulties are at least partially explained by pre-existing vulnerabilities rather than by a direct contribution of exposure to bullying. This study highlights the need to take active measures to prevent exposure to bullying, the importance of addressing potential pre-existing vulnerabilities, and sheds light on the potential for resilience in children who are exposed to peer victimisation. Future research should investigate the mechanisms for resilience and other protective factors that can be harnessed for future interventions.
A JAMA Psychiatry editorial has been released with the article, and is free to access.