Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 15 1 2020 02 10 55 66 Mohammad Effatpanah School of Medicine, Ziaeian Hospital, International Campus, Tehran University of Medical Science, Tehran, Iran. Mohammad Moharrami School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Gilda Rajabi Damavandi Ziaeian Hospital, Tehran University of Medical Science, Tehran, Iran. Mahdi Aminikhah Department of Epidemiology and Biostatistics, School of Public health, Tehran University of Medical Science, Tehran, Iran. Mohammad Hosein Nezhad Farhangiyan University, Tehran, Iran. Farnaz Khatami Family Medicine Department, Ziaeian Hospital, Tehran University of Medical Science, Tehran, Iran. Tara Arjmand Ziaeian Hospital, Tehran University of Medical Science, Tehran, Iran. Heliya Tarighatnia Ziaeian Hospital, Tehran University of Medical Science, Tehran, Iran. Mir Saeed Yekaninejad Farhangiyan University, Tehran, Iran. 2018 10 09 Objective: This study aimed to measure the prevalence of internet addiction and its impact on the psychological well-being of adolescents in Tehran, considering the sociodemographic characteristics. Method: In this cross sectional study, a total of 945 (mean age of 14.85) students (522 boys and 423 girls) were recruited by 2-stage clustering sampling method in 2017. The Chen Internet Addiction Scale (CIAS) and Youth Self-Report (YSR) were used to measure internet addiction and psychological characteristics, respectively. The data were analyzed using multiple-logistic regression analysis adjusted for internet addiction and sociodemographic variables. Results: Overall, 20% of the adolescents were internet addicts. Gender, consanguineous marriage, and father’s education level were significantly associated with internet addiction. Regarding emotional and behavioral characteristics, internet addiction was significantly associated with the scores of internalizing (OR = 5.03; 95% CI: 3.05-8.28) and externalizing problems (OR = 5.84; 95% CI: 3.61-9.43), the total score of empirical scales (OR = 6.51; 95% CI: 3.71-11.6), and all DSM-oriented scales of the YSR (p < 0.001). Except for school performance, other competency scales had no correlations with internet addiction. Conclusion: Regarding the high prevalence of the internet addiction and its correlation with emotional and behavioral characteristics, students and their parents should be advised of the detrimental impacts of internet addiction and try to focus on its constructive application. https://ijps.tums.ac.ir/index.php/ijps/article/view/1570 https://ijps.tums.ac.ir/index.php/ijps/article/download/1570/903