Maartje Boer

CHAPTER 4 102 Abstract This study examined (1) whether intense and problematic social media use (SMU) were independently associated with adolescent wellbeing, (2) whether these associations varied by the country-level prevalence of intense and problematic SMU, and (3) whether differences in the country-level prevalence of intense and problematic SMUwere related to differences inmobile internet access. Individual-level data came from 154,981 adolescents (M age = 13.5) from 29 countries that participated in the 2017/2018 Health Behaviour in School- aged Children survey. Mental (life satisfaction, psychological complaints), school (school satisfaction, perceived school pressure), and social (family support, friend support) wellbeing were assessed. Country-level data came from aggregated individual-level data and OECD data on internet access. Multilevel analyses indicated that in countries with a lower prevalence of intense SMU, intense users reported lower levels of life satisfaction and family support, and more psychological complaints than non-intense users. In contrast, in countries with a higher prevalence of intense SMU, intense users reported higher levels of family support and life satisfaction than non-intense users, and similar levels of psychological complaints. In all countries, intense users reportedmore friend support than non-intense users. Consistent across countries, problematic users reported lower wellbeing on all domains than non-problematic users. Observed differences in country-level prevalence rates of intense and problematic SMU could not be explained by mobile internet access. Adolescents reporting problematic SMU are particularly at risk of lower wellbeing. In many countries, intense SMU may be a normative adolescent behavior that contributes positively to specific domains of their wellbeing. Keywords: Social media use, problematic social media use, wellbeing, adolescents, cross-national research, HBSC.