Maartje Boer

CHAPTER 9 300 maladaptivecognitions, suchas theperception that engaging in thebehavior of interest (here: SMU) mitigates one’s sorrows or negative feelings. Such distorted thoughts may ultimately lead one to depend on the behavior in question. Building on this model, Caplan’s model of problematic internet use postulates that individuals suffering from low mental health often perceive their social competencies as poor. Consequently, they may develop a preference for online social interaction over face-to-face encounters, because they believe that online their social vulnerabilities are less visible. This preference for online interaction may increase the risk of developing problematic internet-related behaviors (Caplan, 2003). However, these models do not explain why other mental health problems, in particular ADHD-symptoms, may increase adolescents’ sensitivity to SMU problems (Chapter 7). To that end, research on ADHD and addictions could provide some directions. Researchers proposed that people with ADHD are sensitive to developing substance-related addictions, because they use substances for self-medication, for example, because substances calm their restless thoughts (Lambert & Hartsough, 1998; Ohlmeier et al., 2008; Wilens, 2004). Also, ADHD is associated with novelty seeking and longing for external stimuli, which, in turn, could be satisfied with substance abuse (Ballon et al., 2015). Furthermore, adolescents with ADHD may be sensitive to substance addiction because due to their impulsivity they typically lack the self-control to resist impulses to satisfy short-term needs, such as the uplifting effects of substances (Rømer Thomsen et al., 2018). In the same way, adolescents with ADHD-symptoms may be more likely to become dependent on social media to cope with their symptoms, to satisfy their recurring need for entertainment, and/or because of their limited ability to resist impulses to use social media. Extending these theoretical mechanisms, SMU problems may, furthermore, exacerbate the psychological vulnerabilities that could make adolescents sensitive to SMU problems. In our studies, lower mental health was a predictor as well as outcome of SMU problems (Key finding 4; Chapters 5-7). This suggests a downwards spiral of lower mental health, whereby psychologically vulnerable adolescents are more likely to develop SMU problems, which, in turn, strengthens their vulnerabilities. However, our findings suggest that the observed negative effect of SMU problems on mental health did not exclusively affect adolescents with lower mental health. In fact, the observed associations from random intercept cross-lagged panel