Digital Danger in Our Pockets: Effect of Smartphone Overuse on Mental Fatigue and Cognitive Flexibility

Smartphones have become essential to life in Western society. This situation reached its peak, especially during the pandemic period. The possibility that smartphone use has negative impact on brain activity has attracted increasing interest among researchers. Medical faculty students were contacted via e-mail and invited to participate in the study. Participants completed the Smartphone Addiction Scale (SAS), the Mental Fatigue Scale (MFS), and the Cognitive Flexibility Inventory (CFI). The total SAS scores of participants with mental fatigue were significantly higher than those of participants without mental fatigue ( p < 0.001). In the smartphone addiction tendency group, the total MFS scores were significantly higher, and the total CFI scores were significantly lower than the scores of the control group ( p < 0.001 for both). In the logistic regression analysis, the total SAS score was associated with the development of mental fatigue ( B coefficient, 0.031, p < 0.001). This study identified potential relationships between smartphone addiction, mental fatigue, and cognitive flexibility. We suggest that smartphone overuse may be an independent risk factor for the development of mental fatigue.