Is There an Association Between Social Media Use and Mental Health? The Timing of Confounding Measurement Matters

To the Editor Riehm et al¹ report an association between social media use and increased risk of internalizing and combined internalizing/externalizing problems 1 year later (between waves 2 and 3 of Population Assessment of Tobacco and Health study data), controlling for psychopathology and alcohol/marijuana use at wave 1. However, the analytic strategy is vulnerable to substantial residual confounding.