Personality Trait Dimensions and Depressive Symptoms among Medical Students: Sequential Mediation Through Psychological Capital and Perceived Stress.

Background:Depressive symptoms (DSs) are highly prevalent among medical students and may adversely affect both student well-being and future healthcare quality. Although personality traits (PTs) are closely associated with mental health, the psychological processes underlying these associations remain incompletely understood. This study examined the associations between the five PT dimensions and DS and explored whether psychological capital (PsyCap) and perceived stress (PS) statistically mediated these associations. Methods:A multicenter cross-sectional survey was conducted among 583 third-year undergraduate clinical medicine students from three medical universities in China. Standardized questionnaires were administered to assess PTs, PsyCap, PS, and DS. Correlation, regression, and sequential mediation analyses were performed. Results:Correlation analyses showed that neuroticism was negatively correlated with PsyCap and positively correlated with PS and DS, whereas extraversion, openness to experience, agreeableness, and conscientiousness demonstrated the opposite pattern (all p < 0.001). Regression analyses indicated that neuroticism, openness to experience, agreeableness, and conscientiousness were significantly associated with DS (β = 0.39, -0.14, -0.15, -0.10, respectively, all p < 0.001), whereas the direct association between extraversion and DS was not statistically significant (β = -0.05). Mediation analyses supported statistically significant indirect associations through PsyCap alone, PS alone, and the proposed sequential pathway through PsyCap and PS. Among the five PT dimensions, the association between extraversion and DS was primarily reflected through the indirect pathways. Conclusion:The findings suggest that PTs may be associated with DS through psychological resources and stress appraisal. By integrating PsyCap and PS into a sequential mediation framework, this study provides an expanded perspective on the psychological processes linking PTs and DS among medical students. Given the cross-sectional design, the proposed mediation pathways should be interpreted as statistical associations rather than causal relationships. Future longitudinal and intervention studies are needed to further evaluate these associations.