Network analysis of non-suicidal self-injury risk: school bullying, depressive symptoms, and psychotic-like experiences in 15,968 Chinese students

Abstract

Non-suicidal self-injury (NSSI) is a major public health concern. While several factors have been associated with NSSI, their complex interactions and joint effects on NSSI remain unclear. This study examined the factors associated with NSSI using network analysis. This cross-sectional study included 15,968 students aged 12–24 years from Hunan province, China, selected using convenience sampling between October 2021 and October 2022. An online questionnaire was administered to collect information on students’ demographics, school bullying victimisation, psychotic-like experiences (PLEs), depressive symptoms, and NSSI. Network analysis was employed to explore the relationships among these factors and identify highly connected or bridge nodes. The chain mediation model was used to assess the mediating factors between school bullying victimisation and NSSI. The network did not exhibit isolated nodes and demonstrated robust connectivity. Node P12 (distracted by distant sounds) showed the highest strength centrality. Nodes P14 (paranoid thoughts) and D9 (suicidal ideation) showed relatively high bridge strength, suggesting their potential role in cross-domain connectivity. Moreover, the verbal bullying victimisation node showed no direct link to any of the NSSI indicators. Instead, PLEs and depressive symptoms served as chain mediators, linking verbal bullying victimisation to NSSI. These findings provide a symptom-level perspective on the associations among school bullying victimisation, PLEs, depressive symptoms, and NSSI among Chinese students. Highly connected and bridge nodes may inform future screening, risk assessment, and longitudinal research.