From Problematic Smartphone Use to Cognitive Decline: The Mediating Role of Doom Scrolling Among Students Receiving Sport Education, A Structural Model

Background The pervasive use of smartphones has raised concerns about their cognitive and psychological consequences among young adults. Problematic smartphone use has been linked to attentional disruption and mental fatigue, while doom scrolling —the repetitive consumption of distressing online content—has emerged as a maladaptive digital behavior that may intensify cognitive strain. Despite growing interest in digital fatigue, studies simultaneously examining problematic smartphone use, doom scrolling, and brain rot—defined as perceived cognitive fatigue resulting from excessive digital consumption—remain limited, particularly among sport sciences students whose academic and performance demands require sustained attention and cognitive flexibility. Objective This study examined whether problematic smartphone use predicts brain rot and tested the mediating role of doom scrolling among university students receiving sport education. Methods A cross-sectional design was used with 491 sport sciences students. Participants completed validated measures of problematic smartphone use, doom scrolling, and brain rot. Data were analyzed using Structural Equation Modeling (SEM), and mediation effects were tested using bootstrapping procedures. Results Problematic smartphone use positively predicted brain rot (β = 0.62, p < .001). It also significantly predicted doom scrolling (β = 0.61, p < .001), which in turn predicted brain rot (β = 0.20, p < .05). The indirect effect was significant, indicating partial mediation. Conclusion Problematic smartphone use contributes to cognitive fatigue both directly and indirectly through doom scrolling. These findings suggest that interventions should address maladaptive digital behaviors, not only screen time, to protect cognitive well-being.