Internet gaming disorder (IGD) is an important issue that was included as a tentative disorder in the DSM-5. The aim of the present study was to contribute to the increasing understanding of IGD by examining the indirect relationships between psychobiological components of personality, positive and negative affect, and IGD among a sample of Iranian university students. In a cross-sectional study, 481 Iranian university students (50.3% female; Mage= 22.41 years [SD=4.62]) were recruited from four universities and completed self-report psychometric scales, including the Internet Gaming Disorder Scale (IGDS), Temperament and Character Inventory (TCI), and Positive and Negative Affect Schedule (PANAS). Structural equation modeling was used to empirically explore the relationships. The model of positive affect and negative affect being a mediator between psychobiological components of personality and IGD fit the data. Individuals with higher levels of negative affect had higher levels of IGD (r=0.60, p<0.001). Furthermore, bootstrapping results showed that psychobiological components of personality affected IGD via negative affect. Findings demonstrated that negative affect mediated the relationships between temperament dimensions of harm avoidance (β = .126), reward dependence (β = .054), persistence (β = -.127), as well as character dimensions of cooperativeness (β = -.047), and self-directedness (β = -.042) with IGD (all p-values <0.001). Findings contribute to the knowledge in the field, and support the proposed models showing that negative affect appears to have an important role in IGD. Clinical implications and study limitations are discussed.
