- Helen L Fisher, MRC population health scientist1,
- Terrie E Moffitt, professor of social behaviour and development123,
- Renate M Houts, senior research statistician23,
- Daniel W Belsky, postdoctoral fellow34,
- Louise Arseneault, reader in developmental psychology1,
- Avshalom Caspi, professor of personality development123
- 1MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College London, London SE5 8AF, UK
- 2Institute for Genome Sciences and Policy, Duke University, Durham, NC, USA
- 3Departments of Psychology & Neuroscience and Psychiatry & Behavioral Sciences, Duke University
- 4Department of Health Policy and Management, Gillings School of Public Health, University of North Carolina at Chapel Hill, NC, USA
- Correspondence to: H Fisher
- Accepted 15 March 2012
Objectives To test whether frequent bullying victimisation in childhood increases the likelihood of self harming in early adolescence, and to identify which bullied children are at highest risk of self harm.
Design The Environmental Risk (E-Risk) longitudinal study of a nationally representative UK cohort of 1116 twin pairs born in 1994-95 (2232 children).
Setting England and Wales, United Kingdom.
Participants Children assessed at 5, 7, 10, and 12 years of age.
Main outcome measures Relative risks of children’s self harming behaviour in the six months before their 12th birthday.
Results Self harm data were available for 2141 children. Among children aged 12 who had self harmed (2.9%; n=62), more than half were victims of frequent bullying (56%; n=35). Exposure to frequent bullying predicted higher rates of self harm even after children’s pre-morbid emotional and behavioural problems, low IQ, and family environmental risks were taken into account (bullying victimisation reported by mother: adjusted relative risk 1.92, 95% confidence interval 1.18 to 3.12; bullying victimisation reported by child: 2.44, 1.36 to 4.40). Victimised twins were more likely to self harm than were their non-victimised twin sibling (bullying victimisation reported by mother: 13/162 v 3/162, ratio=4.3, 95% confidence interval 1.3 to 14.0; bullying victimisation reported by child: 12/144 v 7/144, ratio=1.7, 0.71 to 4.1). Compared with bullied children who did not self harm, bullied children who self harmed were distinguished by a family history of attempted/completed suicide, concurrent mental health problems, and a history of physical maltreatment by an adult.
Conclusions Prevention of non-suicidal self injury in young adolescents should focus on helping bullied children to cope more appropriately with their distress. Programmes should target children who have additional mental health problems, have a family history of attempted/completed suicide, or have been maltreated by an adult.
We acknowledge the study families and the twins’ teachers for their help and participation. We also thank Michael Rutter and Robert Plomin of the Institute of Psychiatry, King’s College London, UK, and members of the E-Risk team for their dedication, hard work, and insights.
Contributors: HLF was involved in reviewing the literature and in analysing and interpreting data and wrote the draft manuscript. All other authors reviewed the report. TEM was involved in the conception, design, and management of the study and in analysing and interpreting data. DWB contributed to study design and statistical analysis. RMH contributed to statistical analysis. LA was involved in the conception, design, and management of the study. AC was involved in the conception, design, and management of the study and in analysing and interpreting data. HLF is the guarantor.
Funding: The E-Risk Study is funded by the Medical Research Council (MRC; G9806489 and G1002190). Additional support was provided by the Economic and Social Research Council (RES-177-25-0013), the US National Institute of Child Health and Human Development (HD061298), the US National Institute of Mental Health (MH077874), the British Academy, the Nuffield Foundation, and the Jacobs Foundation. HLF is funded by an MRC population health scientist fellowship (G1002366). The sponsors played no part in the design or conduct of the study, the analysis or interpretation of data, or the writing of the article and the decision to submit it for publication.
Competing interests: All authors have completed the Unified Competing Interest form at http://www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; and no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: This study was approved by the UK Multicentre Research Ethics Committee (08/H0305/49). The Joint South London and Maudsley and the Institute of Psychiatry Ethics Committee (UK) approved each phase of the study.
Data sharing: The statistical code and dataset are available from principal investigator Louise Arseneault at.
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