Bullying Victimization and Self-Harm Among Adolescents from Diverse Inner-City Schools: Variation by Bullying Sub-Types and the Role of Sex

Objective: Bullying has consistently been highlighted as a risk factor for youth self-harm. Less is known about associations by bullying sub-type (i.e., physical, verbal, relational, cyberbullying), among boys and girls in diverse urban populations. This study aimed to explore: (1) prevalence of bullying and lifetime self-harm; (2) cross-sectional associations between bullying and self-harm. Both aims investigated bullying sub-types and the role of sex.

Method: Baseline data on bullying victimization and lifetime self-harm were drawn from REACH (Resilience, Ethnicity and AdolesCent Mental Health), an accelerated cohort study of adolescent mental health in London, United Kingdom. Data on baseline self-harm and sex were available for 3,060 adolescents aged 11-14 years (M_age=12.4, 50.6% girls, >80% ethnic minority groups) from 10 schools.

Results: Prevalence of bullying in the past six months was 22.3% and lifetime self-harm was 16.9%. Both were more common in girls than boys (adjusted risk ratios: bullying, 1.13 [1.02,1.25]; self-harm, 1.45 [1.03,1.86]). By bullying sub-type, prevalence estimates ranged from 4.1% (cyberbullying) to 16.6% (physical bullying). Bullying was associated with self-harm (aRR 3.35 [2.89,3.82]) for both girls (aRR 3.61 [3.07,4.14]) and boys (aRR 2.96 [2.27,3.65]), independent of sex, age, free school meals and ethnic group. All sub-types were associated with self-harm (aRRs 3.16-4.34), for girls and boys.

Conclusions: These baseline findings underline the importance of exploring nuances between bullying sub-types and self-harm, by sex or gender.