Personality Traits and Psychological Well-Being Among Medical Students: A Cross-Sectional Study

Background: Medical training is characterized by high academic demands and sustained exposure to stressors. Although the literature suggests robust links between personality and mental health, fewer studies have examined how broad personality traits relate to multidimensional psychological well-being (PWB) among medical students. Methods: In a cross-sectional paper–pencil survey conducted among 115 Polish medical students, personality was assessed with the NEO-FFI (Neuroticism, Extraversion, Openness, Agreeableness, Conscientiousness) and psychological well-being with the 84-item Ryff Psychological Well-Being Scales (autonomy, environmental mastery, personal growth, purpose in life, positive relations, self-acceptance). Descriptive statistics, Pearson/Spearman correlations, and multiple linear regression were applied (α = 0.05). Results: Mean global PWB was moderate-to-high (M = 4.22, SD = 0.57; 1–6 scale). The highest subscale means were personal growth (M = 4.48), purpose in life (M = 4.44), and positive relations (M = 4.41); the lowest were autonomy (M = 3.98), environmental mastery (M = 3.91), and self-acceptance (M = 4.09). Conscientiousness and Extraversion correlated positively with PWB dimensions, whereas Neuroticism showed consistent negative associations. In regression models, Conscientiousness (β = 0.482, p < 0.001) and Extraversion (β = 0.347, p < 0.001) jointly explained 38.7% of global PWB variance; Neuroticism alone predicted 32.4% of variance (β = −0.569, p < 0.001). No significant sex differences in PWB were observed. Conclusions: Personality traits—especially lower Neuroticism and higher Conscientiousness and Extraversion—are strongly linked with better psychological well-being among medical students. Screening and tailored, trait-informed preventive programs (e.g., emotion regulation for high Neuroticism; study planning for lower Conscientiousness; social connectedness for lower Extraversion) may support mental health in medical schools.