Maartje Boer

CHAPTER 6 156 associated with lower life satisfaction and more depressive symptoms, although the strength of these associations was often small (Kelly et al., 2018; Twenge, Joiner, et al., 2018; Twenge, Martin, et al., 2018). Researchers argue that this link could be bidirectional: On the one hand, adolescents who use social media intensively may be sensitive to mental health problems because they spend less time on offline activities that are important to their mental health (Primack & Escobar-Viera, 2017; Underwood & Ehrenreich, 2017). On the other hand, adolescents with more mental health problems may be more inclined to use social media more intensively to find emotional and social support for their problems (Radovic et al., 2017). Some longitudinal studies support these propositions (Frison & Eggermont, 2017; Heffer et al., 2019; Riehm et al., 2019), whereas others found no or only a very small bidirectional association between SMU intensity and mental health (Coyne et al., 2020; Houghton et al., 2018; Orben et al., 2019). The few studies that examined both adolescents’ SMU intensity and SMU problems and their associations with mental health in one model repeatedly showed that SMU intensity was not or only weakly associated with lower mental health, whereas SMU problems were consistently related to lower mental health (Boer, Van den Eijnden, et al., 2020; Shensa et al., 2017; Van den Eijnden et al., 2018). These findings imply that previously found negative associations between high SMU intensity and mental health were possibly driven by a confounding effect of SMU problems. High SMU intensity may not necessarily harm mental health, because frequent SMU may not interfere with life domains that are relevant to adolescents’ mental health, such as offline socializing with friends or family (Boer, Van den Eijnden, et al., 2020). Hence, adolescents who engage in high SMU intensity may be well able to regulate their SMU and to combine it with a healthy lifestyle. Reversely, low mental health may not increase SMU intensity because nowadays, many adolescents use social media intensively to maintain and enhance their social involvement with peers (Anderson & Jiang, 2018; Boyd, 2014; Vannucci & McCauley Ohannessian, 2019). Therefore, high SMU intensity may rather be normative adolescent behavior than behavior that is specific to adolescents with low mental health. Accordingly, we expected that high SMU intensity would not be associated with mental health in any direction.