The Internet and digital technologies are becoming a natural part of university students' education. On the other hand, problematic Internet use represents a modern form of non-substance addiction and affects approximately 13% of the Slovak adolescent population. Research findings suggest that problematic internet use may represent a compensatory coping strategy for deficits in regulating negative emotions. There is currently no evidence regarding whether deficits in emotion regulation and/or the use of specific emotion regulation strategies represent one of the causes of problematic internet use. The aim of the conducted research was to investigate whether the use of particular emotion regulation strategies (cognitive reappraisal and suppression of emotion expression) has an impact on problematic internet use. A within-subjects experimental research design was used with a sample of university students (n = 36). Participants were experimentally induced to experience the emotion of anxiety, which they were asked to regulate using three strategies (cognitive reappraisal, expression suppression, and own strategy). Subsequently, impacts on selected areas of problematic internet use were monitored. Associations between difficulties in emotion regulation (Difficulties in Emotion Regulation Scale - short form), internet addiction (Internet Addiction Scale), subjectively perceived anxiety (State-Trait Anxiety Inventory) and heart rate (pulse oximeter) values were also tested. We found a significant positive correlation between difficulties in emotion regulation and internet addiction, excessive internet use, and lack of control over internet use. The use of cognitive reappraisal more strongly reduced current anxiety, heart rate, and mobile phone use compared to suppressing anxiety expression. Overall, the results support the hypothesis that difficulties in emotion regulation may represent one cause of problematic internet use. Developing adaptive strategies to regulate negative emotions in students may represent an important 21st-century skill for healthy internet use, not only in the educational process.

Keywords: Problematic internet use, emotion regulation, cognitive reappraisal, expressive suppression, university students, anxiety.