From Necessity to Excess: Temporal Differences in Smartphone App Usage–PSU Links During COVID-19

With the growing prevalence of digital media use, increasing attention has been directed toward the impact of smartphone usage patterns on mental health. In particular, the COVID-19 pandemic fundamentally altered daily life, accelerating the integration of smartphones into social and economic activities. This study utilized four years of cross-sectional data (N = 75,450) to examine how different types of smartphone application usages—specifically gaming, social networking services (SNS), and online shopping—are associated with problematic smartphone use (PSU), comparing patterns during and after the pandemic. The findings indicate that excessive gaming had a consistently notable association with PSU across both periods. However, the relationship between SNS and shopping app usage on PSU was significantly stronger after the pandemic. This shift suggests that while such applications served essential roles during the pandemic, their continued and excessive use after the return to face-to-face interaction may potentially contribute to problematic use. These results highlight the evolving nature of smartphone application use and its psychological consequences, underscoring the importance of developing tailored intervention strategies that reflect post-pandemic digital behaviors.