Background: With the increase of cyberbullying, several intervention programmes have been created that aim at reducing cyber-victimisation and perpetration. Objective: Our study presents the effects of the STAnD anti-cyberbullying programme with peer-education both on the short and the long run among lower and upper primary school students, with a focus on the participants’ cyberbullying roles. Method: The sample comprised of 536 students who participated in the intervention programme, involving 36% lower and 64% upper primary school students. Participants were measured by a self-reported questionnaire before and right after the programme, then six months later. Results: The main effect of the STAnD programme was a positive change in the participants’ willingness to engage in help-seeking and their active-defending reaction, although this effect decreased after six months. The changes were larger among lower primary school students compared to upper primary school participants. Conclusion: Our results imply that long-lasting and intensive health promotion programmes are necessary to reach a long-term intervention effect. Anti-cyberbullying programmes should take into consideration participants’ involvement and roles in cyberbullying. As our study was a non-randomised uncontrolled study design, thus interpretation of the effectiveness of the programme is limited.

Introduction: Marked gender differences have been identified in cyberbullying perpetration and victimization in adolescence. Age and phenotypic traits, including impulsivity and problematic internet use may mediate the association between gender and cyberbullying intervention outcomes. This study thus aimed to explore gender differences and the potential mediating role of age, impulsivity and problematic internet use regarding the outcomes of an elementary school cyberbullying program. Methods: The peer-led STAnD project shapes students' attitudes towards cyberbullying, and promotes help-seeking behaviors. Baseline sample consisted of 933 respondents (51.3% females, mean age = 11.25, sd = 1.64), and after a 42.55% drop-out, 536 remained in the sample for 6-month follow-up. Four primary outcome measures represented protective factors against cyberbullying. Results: Three of the intervention outcomes – change in 1) helpline knowledge, 2) empathy towards the victims of cyberbullying, and 3) risk perception regarding online hazards - were best predicted by gender. A gender-specific path analysis model indicated that higher amount of time spent online might put a barrier to changes in risk awareness among females and in help-seeking willingness among males. Conclusions: Future cyberbullying programs may design separate interventions for adolescent boys and girls with different emphasis placed on empathy training, or the barriers to help-seeking.