Abstract
OBJECTIVES: Non-suicidal self-injury (NSSI) is a common mental health and behavioral issue among adolescents. This study aims to investigate the developmental trajectory of adolescent NSSI and gender differences, providing a foundation for better prevention and intervention. METHODS: A longitudinal study was conducted using the Adolescent Self-Injury Scale (ASIS) in a cohort of 1 042 junior high school students from 3 middle schools in Zhangjiajie, Hunan Province. Participants were surveyed 3 times at 6-month intervals. A latent growth curve model was constructed using Mplus8.0 to examine the development trajectory of NSSI, and multi-group comparisons were used to assess gender differences. RESULTS: Detection rates of NSSI at the 3 time points were 43.95%, 44.43%, and 38.36%, respectively. Mean of the intercept factor of the LGCM for adolescent NSSI behavior was 9.540 (P<0.001), and the mean slope was -2.297 (P<0.001). Both the variances of the intercept (σ(2)=169.431, P<0.001) and slope (σ(2)=141.981, P<0.001) were significant, with a significant negative correlation between intercept and slope (r=-0.559, P<0.001). There were no statistically significant gender differences in initial level or rate of change of NSSI behaviors (P>0.05). CONCLUSIONS: NSSI is relatively prevalent among adolescents, with female adolescents experiencing more severe NSSI. Individual differences exist in both the initial level and rate of change of NSSI, and overall, adolescent NSSI shows a decreasing trend over time. No significant gender differences were found in the trajectory of change.