Maartje Boer

CHAPTER 7 192 Abstract Using four waves of longitudinal data collected in 2015-2019 from 1,419 adolescents ( M age = 12.5, 45.9% female, 21.9% immigrant), this study identified trajectories of problematic social media use (SMU) in parallel with trajectories of SMU frequency. Latent class growth analysis identified two subgroups with relatively high levels of problematic SMU over time, of which one showed high (24.7%) and one showed average SMU frequency (15.8%), and two subgroups with persistently low levels of problematic SMU, of which one reported low (22.4%) and one reported high SMU frequency (37.1%). Although both subgroups with higher levels of problematic SMU reported low subjective wellbeing, the group with high SMU frequency showed low self-control, whereas the group with average SMU frequency reported poor social competencies. Keywords : Problematic social media use, social media addiction, wellbeing, adolescents, growth trajectories.