Joint developmental trajectory of school bullying victimization, perpetration and bystander behavior and the mental health in adulthood among sexually and gender diverse youth.

BACKGROUND

School bullying targeting sexually and gender-diverse (SGD) youth is widespread and has lasting effects on mental health. Understanding bullying trajectories can offer insights into prevention and intervention strategies for this group. This study examines the developmental trajectories of school-based bullying victimization, perpetration, and bystander roles among SGD youth and their combined impact on mental well-being over time.

METHODS

Data were drawn from the Sexuality and Gender-Based School Bullying Study (SGSBS), assessing bullying experiences across four educational stages (primary, junior high, high school, and college) based on gender labels, expression, identity, and sexual orientation. Latent Class Growth Models (LCGMs) identified respondents' most probable trajectories for victimization, perpetration, bystander, and joint bullying roles. Associations between these trajectories and mental well-being indicators-depressive symptoms, life satisfaction, and mental disorder diagnoses-were analyzed with covariate adjustments.

RESULTS

Analysis included 520 respondents, revealing three distinct trajectories for victimization, perpetration, and bystander behavior, plus five joint trajectories. Participants in higher-frequency bullying trajectories showed increased depressive symptoms (e.g., coefficient = 7.01, 95 % CI: 4.74, 9.29; P < 0.001 in the frequent victimization, perpetration, & bystander group), more mental disorders (e.g., coefficient = 3.10, 95 % CI: 2.13, 4.07; P < 0.001), and lower life satisfaction (e.g., coefficient = -0.69, 95 % CI: -0.97, -0.40; P < 0.001) than those in lower-frequency trajectories.

CONCLUSION

This study highlights the multifaceted bullying experiences of SGD youth and their long-term impacts on adult mental health and life satisfaction. Findings emphasize the need for inclusive, multi-level interventions addressing the unique bullying experiences of SGD youth across all roles within school and community settings.