The mediating effect of bullying on parental–peer support matching and NSSI behaviour among adolescents

Abstract

Abstract Background Being subjected to bullying is a significant risk factor for non-suicidal self-injury (NSSI) among adolescents. Parental support, peer support, and social connectedness play protective roles in mitigating NSSI in this population. However, the precise impact of the combined effects of parental and peer support on bullying and NSSI requires further investigation. Methods This study employed the Child and Adolescent Social Support Scale, Delaware Bullying Victimisation Scale, Social Connectedness Scale, and the Ottawa Self-Injury Inventory to survey 1277 Chinese adolescents. Polynomial regression analysis and response surface analysis were applied to examine the mediating role of bullying and social connectedness in the relationship between parental and peer support matching and NSSI. Results The results indicate that parental support (r = 0.287, P < 0.001), peer support (r = 0.288, P < 0.001), and social connectedness (r = 0.401, P < 0.001) were protective factors against NSSI in adolescents. Conversely, bullying (r = 0.425, P < 0.001) acts as a risk factor for NSSI in this population. Adolescents with low parental and peer support experienced more bullying than those with high parental and peer support, while those with low parental but high peer support experienced less bullying than those with high parental but low peer support (R^2 = 0.1371, P < 0.001). Social connectedness moderated the effect between bullying and NSSI in this model (β = 0.006, P < 0.001). Limitations Due to the under-representation of participants and lack of longitudinal data support, the explanatory power of causality between variables was limited. Future studies should include national samples and incorporate longitudinal studies to enhance the generalisability and robustness of the findings. Conclusion This study reveals the influence mechanism of parental and peer support matching experienced by adolescents on bullying and NSSI and the moderating role of social connectedness. These findings enrich the developmental theory of adolescent NSSI and provide reference for the prevention and intervention of adolescent NSSI behaviour.