*2.1. Participants*

Different schools of Center-South Italy (I.I.S. "A. Bafile", L'Aquila; I.S.I.S. "E. Mattei" Cerveteri [RM]; Liceo Classico "J. da Todi" Todi [PG]; Licei "T. Campanella", Belvedere M.mo [CS]) have been invited to participate in the study, and a total of 1899 adolescents agreed to participate in the survey (970 males and 929 females; Mage = 15.13; SDage = 1.34 years; range 14–19 years). Together with the number of hours played, the whole sample was also asked to indicate the preferred type of VG. Participants chose different genres of VG (adventure, action, quiz, strategy, arcade, fighting game, role playing game, simulation, sports, educational, and first-person shooter). The different types of video games were divided into two main groups defined as "action video games" (AVG; games mainly based on action, incorporating adventure, action, strategy, fighting game, role playing game, simulation, sports, and first person shooter genres) and "no-action video games" (N-AVG; namely quiz, arcade, and educational kind of video games). Based on these data, it emerged that 40.65% of the total sample preferred AVG, compared with 4.58% that chose N-AVG.

Based on the amount of hours of videogaming, we selected 388 participants by the original sample who composed two subgroups of interest: 188 Heavy Gamers (HG), who reported to play for more than 4 h per week (145 males and 37 females; M-age = 15.12; SD-age = 1.42 years) and 200 Light Gamers (LG), who affirmed to play less than 1 hour per week (43 males and 163 females; M-age = 15.08 years; SD-age= 1.11 years). The analysis conducted on two subgroups highlights that for 70.59%, HG choose AVG, while LG prefer play more with N-AVG (61.34%). This sample of participants was considered for the confirmatory analysis of GAMS.

Finally, among the 388 participants, a sub-sample of 172 participants (defined as Heavy Gamers N = 95, and Light Gamers N = 77) accepted to fill-in the CESD (Center for Epidemiologic Studies Depression Scale) and the STAI (State-Trait Anxiety Inventory) questionnaires.
