Smartphone addiction, physical activity engagement, and sleep quality in Chinese adolescents: a parallel and serial mediation model

Introduction

Excessive smartphone use has become a major public health concern among adolescents, particularly in China where smartphone use is widespread. Although smartphone addiction is consistently associated with poor sleep quality, the mechanisms underlying this association remain insufficiently understood. This study examined whether physical activity engagement and depressive symptoms operate as parallel and serial mediators linking smartphone addiction to sleep quality in Chinese adolescents.