School-based anti-bullying interventions: Evidence and implications

Studies have repeatedly found that children who experience bullying are at increased risk of developing depression, anxiety disorders, and broader psychosocial difficulties later in life. A major meta-analysis of longitudinal studies¹ found that victims of bullying were approximately twice as likely to experience depression in adulthood, even after accounting for other childhood adversities and pre-existing vulnerabilities. 

Similarly, research ² demonstrated that frequent bullying in childhood predicted poorer mental health outcomes up to age 50, including increased anxiety, depression, and suicidality.

One study ³ found elevated risks of agoraphobia, panic disorder and generalised anxiety among adults who had been bullied as children. And recent evidence suggests that the mental health consequences of bullying may extend beyond depression and anxiety to include self-harm and post-traumatic stress symptom ⁴. 

• Whole-school anti-bullying interventions demonstrated the strongest evidence base overall.
• Interventions associated with more positive outcomes typically included multiple coordinated components, rather than isolated activities. For example: strong staff training and engagement, leadership support, pupil participation, peer involvement, school policy change, and attention to the wider school climate and relationships, plus ongoing monitoring - rather than focusing solely on individual bullying incidents. 
• However, outcomes were not consistently positive and implementation is critical. Variability in outcomes may partly reflect differences in implementation fidelity, staff engagement, school context, programme adaptation, and the challenges associated with delivering complex interventions in real-world educational settings. 
• Mental health outcomes and the experiences of minority groups vulnerable to bullying were infrequently examined across studies, although one identified study of a targeted intervention found a reduction in victimisation among high-risk pupils. 
• While international studies provide valuable insights, much of the current evidence base originates from outside the UK, limiting understanding of how interventions perform within UK educational, policy, and implementation contexts. Evidence in secondary school settings is particularly limited. 
• Overall study quality was moderate to high. However, methodological limitations were common across the evidence base, particularly those associated with conducting research in applied school settings, where blinding participants to intervention allocation was often not feasible. This rapid evidence assessment however considered only randomised controlled trial studies. While these are methodologically sound, they may not capture insights which may be available in the larger body of literature. We will be continuing our research in this field.

1. Schools should prioritise whole-school anti-bullying approaches that address staff engagement, pupil participation, peer involvement, and school policy, climate, and relationships. 

2. Schools implementing anti-bullying programmes should ensure sufficient attention is given to implementation fidelity, including staff training, leadership support, and ongoing monitoring. 

Recommendations for policymakers and educational organisations 

1. Policymakers and organisations supporting schools should recognise that successful implementation may require sustained resources, training, and long-term support rather than one-off intervention delivery. 

2. Charities working within bullying prevention and youth wellbeing should continue supporting evidence-informed whole-school approaches, while also helping schools address barriers to implementation in practice. 

3. Policymakers should develop a consistent national approach to bullying measurement and monitoring across schools. Guidance and obligations on the use of standardised bullying and wellbeing measures, plus any necessary database adaptations and support, would support more robust evaluation acknowledging that wellbeing effects may not be immediate and collection of longer-term data is key.  

Recommendations for research

1. Greater investment is needed in high-quality UK-based evaluations of anti-bullying interventions. Future evaluations should place greater emphasis on understanding how, for whom, and under what conditions interventions are effective.
2. Greater research attention should be given to how bullying, and anti-bullying interventions, impact vulnerable and minority groups, including LGBTQ+ and ethnic minority pupils. 
3. Researchers should work towards greater consistency in bullying and wellbeing outcome measurement, using validated and standardised measures, to improve comparability across studies. 
4. Future studies should place greater emphasis on evaluating the mental health and wellbeing impact of anti-bullying interventions, including the longer-term effects.