Although many studies have documented the psychometric properties of the Internet Addiction Test (IAT) in adults, its factorial structure has not adequately been investigated in adolescents. The aim of this study was to investigate the psychometric properties of the Internet Addiction Test, specifically testing its factorial structure in a sample of adolescents. A modified version of the Greek IAT, adapted for adolescents, was administered to 725 Greek secondary-school students. To determine the factorial structure underlying the questionnaire, both traditional and bifactor modelling approaches were applied to derive the optimal measurement structure of the IAT for adolescents. The bifactor model supported the single and three distinct factors, with stronger support for the unidimensionality of the instrument. The present study supports the stability of the three-factor structure of the Greek IAT from adolescence to adulthood, yet a longitudinal study is warranted to confirm this suggestion
