The effect of municipality-level social media use on youth mental health

Abstract Background Rising internalizing problems (e.g., depression and anxiety) among youth, particularly among females, have raised concerns about potential societal causes. Social media use (SMU) has emerged as a key focus, given its widespread adoption since the early 2010s. While small to moderate correlations are typically reported between SMU and internalizing problems on the individual level, a complementary community-based perspective allows for assessing the effects of living in environments with high or low social media use on youth mental health. Methods This study investigates the effect of SMU on internalizing symptoms among Norwegian youth in a longitudinal study at the municipality level. The study uses data from the nationwide Ungdata surveys (2014–2024), covering 528 cohorts across 181 municipalities, comprising 40 014 individual responses. Anxiety and depressive symptoms were assessed using items adapted from the Hopkins Symptom Checklist and the Depressive Mood Inventory, respectively. We applied a Bayesian multilevel model, ac