Internet addiction test was used to assess the severity of the tendency to IGD in this study. The IAT consists of 20 items and the answers of these questions were described as 1–5 score (1 = “rarely” to 5 = “always”) (31). The total score of 20 items measures the severity of Internet dependency. The experience of online game playing was assessed via a self-report questionnaire that questioned about the length and amount of playing. The total time of playing online game was calculated as hours per day multiplied by the days of playing online games. Intelligence Quotient (IQ) of all participants was tested using Standard Raven’s Progressive Matrices. The anxiety and depression were texted by using the self-rating anxiety scale (SAS) and the self-rating depression scale (SDS).