Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 0 0 2026 10 27 1 11 Qasim Kadhim Ashour Paediatric Nursing Department, College of Nursing, University of Kerbala, Kerbala, Iraq. Khatam Matsher Al-Musawi Paediatric Nursing Department, College of Nursing, University of Baghdad, Baghdad, Iraq. 2026 06 13 2026 09 21 Objective: This study aimed to examine the serial mediating roles of sleep disturbance and emotional dysregulation in the relationship between social media addiction and academic performance among school-aged children aged 6-12 years. Method: A cross-sectional explanatory study was conducted among 760 school-aged children aged 6-12 years recruited from primary schools in Holy Kerbala City, Iraq, using stratified cluster random sampling. Data were collected using four validated instruments: The Social Media Addiction Scale-Student Form (SMAS-SF), the Children's Sleep Habits Questionnaire (CSHQ), the Difficulties in Emotion Regulation Scale-Short Form (DERS-SF), and a standardized School Performance Scale. Serial mediation analysis was conducted using structural equation modeling (SEM) with bootstrapping to test the hypothesized pathway. Results: The prevalence of moderate-to-severe social media addiction was 68.4%, with a mean SMAS score of 99.2 (SD = 17.4). Mean sleep duration was only 5.8 hours (SD = 1.3), far below the recommended 9-12 hours. Emotional dysregulation was markedly elevated (mean DERS = 56.3, SD = 12.1). The serial mediation model demonstrated good fit (CFI = 0.93, RMSEA = 0.061). Social media addiction had a significant negative total effect on academic performance (β = -0.44, P = 0.001). The total indirect effect through the serial pathway was significant (β = -0.18, 95% CI: -0.24 to -0.12), accounting for 40.9% of the total effect. The specific serial indirect effect (addiction → sleep disturbance → emotional dysregulation → performance) was β = -0.08 (95% CI: -0.12 to -0.04). Maternal education (P = 0.009) and family income (P < 0.001) were significantly associated with addiction severity. Conclusion: Emotional dysregulation is a significant serial mediator linking social media addiction to poor academic performance through sleep disturbance. These findings support social learning theory, suggesting how maladaptive media habits may disrupt biological (sleep) and emotional regulatory systems. School-based interventions should target not only sleep hygiene, but also emotion regulation skills training. https://ijps.tums.ac.ir/index.php/ijps/article/view/4657 https://ijps.tums.ac.ir/index.php/ijps/article/download/4657/1358