Heterogeneities by Age and Sex in Associations Between Electronic Device Use Frequency and Comorbid Mental Health Symptoms: The Roles of Self-Efficacy and Social Support

Objectives: This study aims to examine age and sex disparities in the relationships between the weekly frequency of electronic device use and mental health comorbidities (anxiety symptoms, depressive symptoms, and stress), and the roles of self-efficacy and social support. Methods: Data were derived from the 2021 Psychology and Behavior Investigation of Chinese Residents (PBICR), which adopted a cross-sectional research design using a self-reported questionnaire-based survey. Random forest models were performed to examine the role of electronic device use on mental health, multinomial logistic regressions were conducted to quantify the associations, and mediation analyses via structural equation modeling were conducted to explore the roles of self-efficacy and social support, and all analyses were conducted by stratifying age and sex. Results: Of the 11,031 participants, 23.58%, 18.88%, and 16.91% of the young, the middle-aged, and older people reported mental health comorbidities, respectively. The weekly frequency of mobile phone use was identified as the second most important predictor of mental health comorbidities in adolescents and the young, as well as middle-aged adults. High-frequency mobile phone use was inversely associated with comorbidities, especially in young and middle-aged males. Low- and mid-frequency computer use were positively associated with comorbidity, especially in all males. The weekly frequency of mobile phone use played no significant direct role, and the significant direct association of weekly frequency of computer use was identified in middle-aged and older males. The mediating roles of self-efficacy and social support presented age and sex disparities. Conclusions: Despite the inherent limitations of cross-sectional, self-reported weekly data, the present findings highlight that policymakers and clinicians should consider the dual-edged role of digital device use in mental health, leveraging its benefits through tailored digital interventions while mitigating risks across diverse demographic groups.