Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 47 7 2018 07 16 Effect of Competitive and Non-competitive Exercise on Serotonin Levels in Adolescents with Various Levels of Internet Gaming Addiction 1047 1049 So-Hyung KANG Dept. of Sports and Wellbeing, Arts & Sports, Hanyang University, Ansan-si, Korea Wi-Young SO Sports and Health Care Major, College of Humanities and Arts, Korea National University of Transportation, Chungju-si 27469, Korea 2018 07 16 2018 07 16 Effect of Competitive and Non-competitive Exercise on Serotonin Levels in Adolescents with Various Levels of Internet Gaming Addiction https://ijph.tums.ac.ir/index.php/ijph/article/view/14056 https://ijph.tums.ac.ir/index.php/ijph/article/download/14056/6051