Disentangling stress, anxiety, and depression in the relationship between insomnia and nomophobia among medical students

Nomophobia is an increasing concern among medical students, yet the psychophysiological mechanisms linking sleep disturbances to this maladaptive health behavior remain insufficiently understood. Guided by the I-PACE model, this study examined whether stress, anxiety, and depression mediate the correlation between insomnia and nomophobia, conceptualizing insomnia as a physiological vulnerability factor. This cross-sectional study included 201 medical students (38.3% preclinical phase and 61.7% clinical phase). Participants completed the Nomophobia Questionnaire, Depression Anxiety Stress Scales, and Insomnia Severity Index. Parallel mediation analysis revealed that although insomnia was correlated with all distress variables, stress emerged as the only significant unique mediator, indicating an indirect-only mediation pattern. Anxiety and depression showed non-significant effects due to statistical suppression, and a reverse model yielded no significant indirect effects. These findings suggest that insomnia contributes to nomophobia primarily through heightened stress, underscoring the importance of sleep hygiene and stress regulation in preventive health interventions for medical students.