Original citation: Wolke, Dieter, Tippett, Neil and Dantchev, Slava. (2015) Bullying in the family : sibling bullying. The Lancet Psychiatry. Permanent WRAP url:http://wrap.warwick.ac.uk/67729 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work of researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-forprofit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher statement:http://www.thelancet.com/journals/lanpsy/issue/current A note on versions: The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. AbstractSibling relationships have a significant and lasting impact on children's development. Many siblings experience some occasional conflict, however, up to 40% are exposed to sibling bullying every week, a repeated and harmful form of intra-familial aggression. Evidence on the precursors, relationship with peer bullying, and mental health consequences of sibling bullying are reviewed. Parenting quality and behaviour are the intra-familial factors most strongly related to bullying between siblings. Sibling bullying increases the risk of being involved in peer bullying, and is independently associated with concurrent and early adult emotional problems, including distress, depression and self-harm. The effects appear to be cumulative, with those bullied by both siblings and peers having highly increased emotional problems, likely because they have no safe place to escape from bullying. The link between sibling and peer bullying suggests interventions should start at home. Health professionals should ask about sibling bullying and interventions are needed for families to prevent and reduce the health burden associated with sibling bullying.Bullying in the Family: Sibling Bullying

Parents and health professionals should be aware of the adverse long-term effects of sibling bullying.

Sibling and peer bullying are reported as the most frequent forms of violence experienced across childhood. There is now ample evidence indicating an association between sibling and peer bullying, with those reporting sibling bullying at an increased risk of peer bullying. While there is convincing evidence of a causative association between peer bullying and a range of mental health outcomes, sibling bullying continues to receive far less attention. The aim of this study was to explore whether sibling bullying roles (non-involved, victim, bully-victim, bully) in middle childhood were independently associated with clinical diagnoses of depression and anxiety and reports of suicidal ideation and self-harm in early adulthood. We further tested whether there was a cumulative relationship between involvement in sibling and peer bullying victimization. This study was based on up to 3,881 youth from the Avon Longitudinal Study of Parents and Children, a prospective birth-cohort based in the United Kingdom. Sibling and peer bullying was assessed via self-report when youth were 12 years of age, while depression, anxiety, suicidal ideation, and self-harm were assessed via self-administered computerized interviews at 24 years of age. Involvement as a sibling bully-victim was associated with clinical diagnosis of depression (OR = 1.91, 95% CI: 1.33–2.72), while sibling victims were at increased odds of both suicidal ideation (OR = 1.52; 95% CI, 1.16–1.98) as well as suicidal self-harm (OR = 2.20, 95% CI, 1.36–3.58) in early adulthood, even after accounting for concurrent peer bullying and a range of other pre-existing childhood confounders. Sibling and peer bullying were further associated in a homotypic manner. A dose–response relationship of bullying in the home and school across mental health outcomes was found. Youth victimized by both their siblings and peers displayed the highest odds of developing clinical depression, suicidal ideation, and self-harm. Children bullied at home and at school had no safe place to escape the bullying and torment. Our findings highlight the need for intervention studies tailored toward reducing sibling bullying, as these may hold large promise for alleviating a range of adverse outcomes, including the prevention of peer bullying, which may be contingent on early bullying experiences in the home environment.