Bullying behavior and mental health among college students in Sichuan, China: a cross-sectional study

BackgroundBullying is a known risk factor for poor mental health in adolescents. Although bullying research has largely focused on adolescent populations, college students represent a distinct group warranting dedicated attention. They shoulder unique developmental tasks including academic competition and career preparation, and exhibit behavioral characteristics of frequent engagement with digital platforms. This study examined the prevalence of bullying and its associations with depression, anxiety, and post-traumatic stress disorder (PTSD).MethodologyA cross-sectional survey was conducted among 1,120 students from August 18 to September 10, 2025. We recruited participants from a single college through class-based online channels using convenience sampling. Standardized scales assessed bullying experiences, anxiety, depression, PTSD symptoms, and psychological resilience.ResultsA total of 241(21.5%) students reported being bullied, and 101(9.0%) reported bullying others. Mann–Whitney U tests showed no significant effects of age and ethnicity on the four mental health indicators (all p > 0.05). Gender and family residence groups exhibited statistically significant differences in GAD-7 and PHQ-9 scores; additionally, family residence groups differed in CD-RISC-25 scores (p < 0.05). Regression analyses indicated that traditional bullying victimization and cyberbullying victimization were significant factors associated with higher anxiety, depression and PTSD scores (β range: 0.280–0.561, all p < 0.001). Traditional bullying victimization was also associated with lower psychological resilience (β = −0.134, p = 0.009). The sensitivity analysis reveals that the inverse association observed between traditional bullying and certain indicators may be driven by suppression effects.ConclusionThe findings highlight the need for campus-based mental health screening, early identification of bullying involvement, and targeted bullying prevention initiatives among university students. Specifically, given that cyberbullying victimization showed a stronger association with PTSD symptoms compared to traditional bullying, trauma-focused interventions should be prioritized for cyberbullying victims to alleviate PTSD symptoms. In contrast, traditional bullying victims may benefit from resilience enhancement programs.