Peer victimization as a potential gendered mediator between BMI and depression in adolescents from Jiangsu province,...

This study aimed to examine whether peer victimization and behavioral factors serve as potential mediators in the association between body mass index (BMI) and depressive symptoms among adolescents in Jiangsu Province, China, with a specific focus on gender-specific and non-linear interactions.

A cross-sectional survey.

Participants were 5187 adolescents (median age = 14.43) from Jiangsu Province, China. BMI was classified per Chinese national standards. Depressive symptoms were assessed using the CES-D-20, and peer victimization was processed using a non-linear weighting scheme (0-1-5) and Principal Component Analysis (PCA) to capture severity. Structural equation modeling (SEM) was employed to evaluate potential mediation pathways, while Response Surface Analysis (RSA) was utilized to decode complex non-linear interactions between BMI and victimization intensity.

In the overall sample, peer victimization was a significant potential mediator, accounting for 57.9% of the total association between BMI and depression, primarily through emotional neglect (81.7%) and verbal victimization (53.2%). A stark gender disparity was identified: the potential indirect pathway was strong and consistent in females (accounting for 89.4% of the association) but was absent in males. RSA further revealed distinct risk trajectories: males showed a significant positive curvature for emotional neglect (a₂ = 0.192, P = 0.029), explaining the lack of linear mediation in the male subgroup.

Peer victimization, particularly emotional neglect and verbal victimization, is a pivotal potential gendered mediator linking BMI to depression among adolescents in this region. The mental health burden of obesity is shaped by distinctly gendered social experiences and non-linear risk trajectories.