KMAN Publication Inc. (KMANPUB) Journal of Adolescent and Youth Psychological Studies (JAYPS) 2981-2526 7 Serial Number 49 2026 09 10 Serial Mediation of Rumination and Emotion Dysregulation in the Relationship Between Peer Victimization and Adolescent Depression Serial Mediation of Rumination and Emotion Dysregulation in the Relationship Between Peer Victimization and Adolescent Depression 1 16 EN Journal Article 2026 04 26 <table> <tbody> <tr> <td> <p><strong>Objective:</strong> This study aimed to examine the serial mediating roles of rumination and emotion dysregulation in the relationship between peer victimization and depressive symptoms among adolescents in Mexico.</p> <p><strong>Methods and Materials:</strong> This cross-sectional correlational study was conducted among 657 adolescents aged 13–18 years enrolled in public and private secondary and upper-secondary schools in Mexico City during the 2025–2026 academic year. Participants were selected through multistage cluster sampling. Peer victimization was assessed using the Multidimensional Peer Victimization Scale, rumination using the rumination subscale of the Children’s Response Styles Questionnaire, emotion dysregulation using the Difficulties in Emotion Regulation Scale, and depressive symptoms using the Patient Health Questionnaire-9. Data were analyzed using IBM SPSS Statistics version 29 and PROCESS macro Model 6. Pearson correlations, multiple regression analyses, and serial mediation analysis with 5,000 bootstrap resamples were performed. Age and sex were entered as covariates, and indirect effects were considered significant when 95% bootstrap confidence intervals excluded zero.</p> <p><strong>Findings:</strong> Peer victimization significantly predicted rumination (β = .47, p &lt; .001), emotion dysregulation (β = .13, p &lt; .001), and depressive symptoms (β = .15, p &lt; .001). Rumination significantly predicted emotion dysregulation (β = .55, p &lt; .001) and depressive symptoms (β = .25, p &lt; .001), while emotion dysregulation significantly predicted depressive symptoms (β = .45, p &lt; .001). The final model explained 51% of the variance in depressive symptoms, F(5, 651) = 133.74, p &lt; .001. The total indirect effect of peer victimization on depression was significant (B = 0.31, 95% Boot CI [0.25, 0.38]). The serial indirect pathway through rumination and emotion dysregulation was also significant (B = 0.12, 95% Boot CI [0.09, 0.16]).</p> <p><strong>Conclusion:</strong> Peer victimization was associated with adolescent depressive symptoms both directly and indirectly through a sequential cognitive-emotional pathway involving increased rumination followed by greater emotion dysregulation.</p> </td> </tr> </tbody> </table> https://journals.kmanpub.com/index.php/jayps/article/download/6236/11940