strongest in countries like Hungary, Sweden, Latvia, and the Netherlands (with coefficients across age groups (11-12, 13-14, and 15-16), reaching approximately -0.25), and more muted in others, including Azerbaijan, Georgia, Kazakhstan, First, we observe that PSMU is consistently and Turkiye (where coefficients are closer to -O.06 to -O.ll). These coefficients are about one-third groups. Across regions, a one-unit increase in 0.12-0.15 points in psychological complaints and served school characteristics and to avoid biased estimates, controlling for gender and frequency of social media and 95% confidence intervals are shown. P-values are shown for interaction effects, where age 1l-12 is the reference