Patterns of screen time and smartphone addiction and their relation to mental health among university students in Lebanon: a cross-sectional study

Smartphone use has become increasingly prevalent among university students, raising concerns about its potential impact on mental health. While previous studies have reported associations between smartphone addiction, screen time, and psychological distress, findings remain inconsistent, and few studies have used device-recorded smartphone use. Therefore, this study aimed to examine the associations of smartphone addiction and screen time with depressive and anxiety symptoms among university students in Lebanon using device-recorded screen-time data. Participants completed a cross-sectional online survey containing validated tools: smartphone addiction was assessed using the Smartphone Addiction Scale (SAS), depressive and anxiety symptoms were evaluated using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) questionnaires, respectively. Smartphone variables such as screen time were objectively measured using the data from smartphone settings. Multivariable regression analyses were performed to examine the associations. Among 404 students, mean daily screen time was 6.33 ± 2.50 h. Smartphone addiction was independently associated with greater depressive symptom severity (B = 0.088, 95% CI: 0.046–0.129, p < 0.001), while screen time was associated with greater anxiety symptom severity (B = 0.169, 95% CI: 0.018–0.321, p = 0.028). The screen time × smartphone addiction interaction was significant for depressive symptoms (B = 0.029, 95% CI: 0.012–0.045, p = 0.001), with greater screen time associated with fewer depressive symptoms at relatively low addiction levels and greater depressive symptoms at relatively high addiction levels. No significant interaction was observed for anxiety symptoms (B = 0.002, 95% CI: −0.014 to 0.017, p = 0.833). Smartphone addiction and screen-time duration showed distinct associations with mental health outcomes, and the association between screen time and depressive symptoms varied according to the level of smartphone addiction. These findings highlight the importance of considering both the duration and pattern of smartphone use when examining its relationship with mental health. Longitudinal studies are needed to clarify the temporal direction of these associations. Not applicable.