Prevalence of Social Media Addiction and Associations With Usage Patterns, Burnout, and Health Conditions Among Medical Trainees in China: Cross-Sectional Study.

Background: Medical residency is a demanding training stage characterized by high levels of stress and burnout. As digital natives, current medical trainees (ie, residents) are frequent users of social media; however, little is known about how their personal (nonprofessional) use relates to burnout and social media addiction (SMA). Objective: This study aims to characterize the prevalence of SMA among Chinese medical trainees and explore its complex relationships with social media use patterns, occupational burnout, and related risk and protective factors. Methods: A nationwide cross-sectional survey was deployed through Wenjuanxing and disseminated via WeChat between August 29 and September 10, 2024. Data included demographics, physical and psychiatric health history, work variables (eg, training year and night shifts), personality traits, and social media use. SMA was assessed using the Bergen Social Media Addiction Scale. Logistic regression was performed to identify predictors of addiction, and mediation and moderation analyses were conducted to clarify the role of occupational burnout. Results: Of 3621 medical trainees, 211 (5.8%) met the criteria for SMA (Bergen Social Media Addiction Scale ≥24, indicating addiction). Second-year medical trainees reported the highest addiction prevalence (92/1159, 7.9%). Logistic regression analysis revealed that higher burnout (odds ratio [OR] 1.41, 95% CI 1.23-1.62; P<.001), longer daily use (OR 1.39, 95% CI 1.23-1.56; P<.001), physical health problems (OR 1.56, 95% CI 1.13-2.16; P=.006), and psychiatric history (OR 2.00, 95% CI 1.41-2.84; P<.001) significantly increased the odds of addiction, whereas conscientiousness was protective (OR 0.92, 95% CI 0.86-0.99; P=.02). Social media use showed significant U-shaped associations with burnout, physical health problems, psychiatric history, personality characteristics, and mental health outcomes. For example, medical trainees using social media 1 hour or less (104/404, 25.7% with psychiatric history) and more than 4 hours daily (97/419, 23.2% with psychiatric history) both had higher risk profiles than moderate users. Mediation analysis showed that occupational burnout explained 28.1% of the effect of psychiatric history and 29.6% of the effect of physical health problems on addiction risk. Conclusions: This large-scale survey provides the first systematic characterization of SMA among Chinese medical trainees and elucidates its associated risks and protective factors. Burnout consistently emerged as a key and pervasive predictor of SMA, functioning both as an independent risk factor and as a mediator amplifying the impact of health-related vulnerabilities. Moreover, the findings highlight that both minimal and excessive daily social media use may signal distinct behavioral manifestations of distress, potentially reflecting different clinical phenotypes: digital disengagement under acute stress versus compulsive engagement driven by chronic burnout. Notably, while mental health symptoms exhibited U-shaped associations with usage, SMA risk increased progressively with daily duration. These results underscore the need for interventions that extend beyond simply monitoring usage duration, emphasizing strategies to reduce burnout and enhance the overall well-being of medical trainees.