Supplementary Material for: European Portuguese version of the Game Addiction Scale-7 (GAS-7-PT): Factor structure and psychometric properties

Introduction: Game addiction (GA) can be described as a compulsive and excessive usage of computers or video games that causes emotional and or social problems. The current study tested the factor structure and psychometric properties of the European Portuguese Game Addiction Scale (GAS-7-PT) short version. Methods: The sample encompassed 375 participants, 233 women (62.1%) and 142 men (37.9%), with a mean age of 21.71 (SD=5.82) years old. Participants completed a set of self-report measures online: the GAS-7-PT, the Scale of Involvement in Video Games and the Patient Health Questionnaire-4. Results: Confirmatory factor analyses confirmed a biological sex invariant single-factor structure with a very good fit to the data. The GAS-7-PT showed good reliability and test-retest reliability. Correlations with related and unrelated measures suggested convergent validity, and partial correlation results pointed to incremental validity. Men showed significantly higher scores than women. Conclusion: The GAS-7-PT is a self-report instrument with suitable psychometric properties for clinical and research contexts. The availability of a European Portuguese version confirms the GAS-7 robust consistency and allows further cross-cultural clinical research.