Few questions generate more parental anxiety than whether social media is damaging teenagers' mental health. A longitudinal Karolinska Institutet study in the Journal of Adolescent Health offers a measure of reassurance. Researchers surveyed over 5,500 Swedish pupils aged 15 to 16 in 2017 and followed up with just over 3,000 of them five years later, asking about symptoms of depression and anxiety in young adulthood.
At the initial measurement, heavier social media users did report slightly more mental health problems, consistent with the cross-sectional correlations that dominate public debate. But the longitudinal picture was different: five years on, only a weak association remained between adolescent social media time and later symptoms, and it disappeared entirely after adjustment for earlier mental health, gender, socioeconomic status and physical activity. Time spent on platforms at 15, in other words, did not predict mental ill-health at 20.
The authors, including Jonas Raninen and Geir Scott Brunborg, acknowledge the study's limitations: social media use was self-reported at a single time point in 2017, younger teenagers were not covered, and the platforms themselves have evolved considerably since the baseline survey. Their conclusion points future research somewhere more productive: towards what young people actually do online, and which groups are vulnerable, rather than towards raw counts of hours spent on screens.