Maartje Boer

VALIDATION OF THE SMD-SCALE 27 2 Validation of the Social Media Disorder-Scale in Adolescents: Findings from a Large-Scale Nationally Representative Sample Social network sites and instant messengers such as Instagramand Snapchat have become prominent parts of adolescents’ lives (Anderson & Jiang, 2018). The social involvement and entertainment that are associated with social media use (SMU) may enhance adolescents’ social capital and feelings of connectedness (Verduyn et al., 2017). However, SMU can become concerning when it is associated with addiction-like symptoms, such as a loss of control over SMU (Griffiths et al., 2014), which we refer to as problematic SMU . Research has shown that adolescent problematic social media users are more likely to experience mental health problems (Marino et al., 2018b; Van den Eijnden et al., 2018), have lower school achievements (Al-Menayes, 2015b; Vangeel et al., 2016), and lower sleep quality (Andreassen et al., 2012; Wong et al., 2020). While these studies emphasize the potential threat of problematic SMU to adolescents’ development and daily life functioning, validation work on instruments that measure problematic SMU is limited. The present study aims to validate the nine-item Social Media Disorder (SMD) Scale (Van den Eijnden et al., 2016) in a Dutch nationally representative adolescent sample. There has been debate for many years about whether heavy engagement in activities, for example in SMU, should be regarded as addictive behaviors (Kardefelt-Winther et al., 2017; Van Rooij et al., 2018). For a long time, diagnostic manuals have linked ‘addiction’ to substance-related disorders only (Potenza, 2014).However, ithasbeenputforwardthatalladdictivebehaviors,eitherrelatedto substancesorbehaviors, result fromsimilar individual biological andpsychosocial processes and share six core criteria of addiction (Griffiths, 2005; Potenza, 2014). These core criteria are: salience (i.e., preoccupation: constantly thinking about the activity in concern), moodmodification (i.e., escape: the activity helps to find relief from negative feelings), tolerance (i.e., wanting to engage in the activity more andmore), withdrawal (i.e., experiencing unpleasant physical or emotional effects when the activity is not possible), conflict (i.e., having conflicts at school, work, or with personal close relationships due to the heavy engagement in the activity), and relapse (i.e.,persistence:beingunabletostopor tocontrol theactivity) (Griffiths, 2005). With the increasing evidence demonstrating the similarities between substance-related disorders and gambling- and gaming disorders, the