Intended for healthcare professionals

CCBY Open access

Rapid response to:

Research

Peer victimisation during adolescence and its impact on depression in early adulthood: prospective cohort study in the United Kingdom

BMJ 2015; 350 doi: https://doi.org/10.1136/bmj.h2469 (Published 02 June 2015) Cite this as: BMJ 2015;350:h2469

Rapid Response:

Re: Peer victimisation during adolescence and its impact on depression in early adulthood: prospective cohort study in the United Kingdom

Our population attributable fraction (PAF) suggested that 29.2% (95% confidence interval 10.9% to 43.7%) of depression at age 18 years could be explained by peer victimisation if this were a causal relation. In a recent rapid response to our article, the author suggests that we “overstate the amount of adult depression associated with peer bullying in adolescence due to serious limitations in their data set”, with the author focusing on “the confounding variable of prior adult bullying in childhood”. Firstly, it is important to note that PAFs are always upper limits - with observational research such as ours there is likely to be some residual confounding. However confounders would have to be very strongly associated with both the exposure and the outcome to make a large difference on their own. We agree with the author that child maltreatment1 is an important factor to take into consideration, given that children who are maltreated are approximately twice as likely to be victimized by peers (Bowes et al., 2009). Maltreated children are about 3 times more likely to be depressed as young adults (Brown et al, 1999), although it has been suggested that this may be an overestimate, with many studies not adjusting for peer victimization (Lereya et al., 2010). In our analyses, we adjusted for maternal reports of children’s exposure to physical or sexual abuse, or having been putting into care between ages 5-7 (i.e. prior to our measure of peer victimization. We agree that this is likely to underestimate the true prevalence of maltreatment, particularly parental maltreatment. Measuring maltreatment is difficult; official records of children referred to social services likely represent only the most severe cases, and it would be unethical to ask young children to report on their own experiences of maltreatment. Our measure, like all measures, is prone to error, however it would have captured some of the confounding effect of maltreatment. While residual confounding cannot be ruled out, we think it unlikely that it could explain an association of this size.
Competing interests: No competing interests
1 When hurtful actions are perpetrated by adults towards children or adolescents, we consider this maltreatment and not bullying (Arseneault, Bowes & Shakoor, 2010).
Arseneault, L., et al. (2010). "Bullying victimization in youths and mental health problems: 'much ado about nothing'?" Psychological Medicine, 40, 717-729.

Bowes, L., et al. (2009). "School, neighborhood and family factors are associated with children's bullying involvement: A nationally-representative longitudinal study." Journal of the American Academy of Child and Adolescent Psychiatry, 48, 545-553.

Brown, J., Cohen, P., Johnson, J. G., & Smailes, E. M. (1999). Childhood abuse and neglect: specificity of effects on adolescent and young adult depression and suicidality. Journal of the American Academy of Child & Adolescent Psychiatry, 38, 1490-1496.
Lereya, S. T., Copeland, W. E., Costello, E. J., & Wolke, D. (2015). Adult mental health consequences of peer bullying and maltreatment in childhood: two cohorts in two countries. The Lancet Psychiatry, 2, 524-531.

Competing interests: No competing interests

25 June 2015
LN Bowes
Leverhulme Early Career Research Fellow
Dr Carol Joinson, Professor Dieter Wolke, Professor Glyn Lewis
University of Oxford
Department of Experimental Psychology, Tinbergen Building, 9 South Parks Road, Oxford, OX1 3UD