Original article: "Smartphone use in a large US adult population: Temporal associations between objective measures of usage and mental well-being" - https://www

Original article: "Smartphone use in a large US adult population: Temporal associations between objective measures of usage and mental well-being" - https://www.pnas.org/doi/10.1073/pnas.2427311122 https://www.pnas.org/doi/10.1073/pnas.2427311122 Notes: They used objective measures of smartphone usage, rather than self-reporting. But the study only measured effects over a 4-week period.