en General پژوهشي Research Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><strong>Background:</strong>Adolescent self-harm is an escalating public health issue, frequently associated with challenges in personality organization and exposure to cyberbullying.<br> <strong>Objectives:</strong>This study examines the direct and indirect relationships among personality organization, cyber-victimization, and self-harm behaviors in adolescents, emphasizing the mediating role of emotion regulation difficulties.<br> <strong>Methods:</strong>Utilizing a descriptive correlational design, we employed multi-stage cluster random sampling to recruit 356 adolescents (65.17% female, 34.83% male) from Tehran in 2024. Data were gathered using validated instruments: The Self-harm Behavior Questionnaire, Personality Organization Questionnaire, Difficulties in Emotion Regulation Scale-Short Form, and Cyber-victimization Scale. Structural equation modeling (SEM) was performed using AMOS software to explore variable relationships.<br> <strong>Results:</strong>The results indicated significant positive associations between personality organization (primitive psychological defenses: 24.76 &plusmn; 6.33; identity diffusion: 22.92 &plusmn; 5.14; reality testing: 40.46 &plusmn; 9.79, cyberbullying (cyber aggression: 15.41 &plusmn; 4.10); cyber victimization: 16.96 &plusmn; 4.18, and self-harm behaviors: 6.06 &plusmn; 1.88 (all P < 0.001). Emotion regulation difficulties (e.g., lack of clarity: 6.77 &plusmn; 2.49); non-acceptance: 9.41 &plusmn; 2.92 significantly mediated the relationships between personality organization, cyberbullying, and self-harm (P < 0.001).<br> <strong>Conclusions:</strong>These findings highlight that compromised personality organization and cyber-victimization are strong predictors of self-harm, with emotion regulation difficulties acting as a crucial mediator. Interventions focused on enhancing emotion regulation skills may reduce the risk of self-harm in adolescents, presenting a promising strategy for prevention and support.</span></span></div> ersonality Organization,Cyberbullying,Self-harm Behaviors,Adolescents 0 0 http://mcj.bums.ac.ir/browse.php?a_code=A-10-1-315&slc_lang=en&sid=1 Mozhdeh Samadi Ahari 10031947532846004897 0009-0006-2398-8690 No Department of Psychology, Ahv.C., Islamic Azad University, Ahvaz, Iran Sahar Safarzadeh s.safarzadeh1152@iau.ac.ir 10031947532846004898 10031947532846004898 Yes Department of Psychology, Ahv.C., Islamic Azad University, Ahvaz, Iran Fatemeh Sadat Marashian 10031947532846004899 10031947532846004899 No Department of Psychology, Ahv.C., Islamic Azad University, Ahvaz, Iran Marzieh Talebzadeh Shoushtari 10031947532846004900 10031947532846004900 No Department of Psychology, Ahv.C., Islamic Azad University, Ahvaz, Iran