Measurement Invariance of the Lemmens Internet Gaming Disorder Scale-9 Across Age, Gender, and Respondents.

Although Internet gaming disorder (IGD) has gained increased attention in scientific, clinical, and community contexts, there is still a lack of consensus regarding the best assessment tools (i.e., self-report or other reports) for assessing its symptoms. The present study aimed to investigate the reliability, validity, and measurement invariance of both versions (youth and parent) of The Lemmens Internet Gaming Disorder Scale-9. To achieve this goal, we recruited between June and October 2019 from five Romanian highschools a total of 697 adolescents (11-19 years old) and one of their parents (N = 391). The internal consistency was good in both versions of the instrument (α = 0.772 for the youth version and α = 0.781 for the parent version). Construct validity assessed through confirmatory factor analysis showed support for the one factor structure of the scales, while multigroup confirmatory factor analysis endorsed the invariance across age, gender, and respondents (i.e., parent vs. youth report). The current research identifies both IGD scales to be reliable and valid, arguing for their utility for assessing IGD symptomatology among adolescents. Implications for theory, assessment, and future directions are discussed.