Abstract
Depression represents a major global mental health challenge, yet protective factors that enhance resilience against depressive symptoms remain insufficiently understood. This two-wave longitudinal study examined prospective relationships between personality traits, spiritual fitness dimensions, positive mental health, and depressive symptoms in Polish adults over six months, determining their relative contributions and investigating mediational pathways. A total of 385 participants completed baseline assessments, with 158 completing six-month follow-up. The combined model explained 41.4% of variance in depressive symptoms. Positive mental health emerged as the strongest protective factor, demonstrating substantially larger effects than individual personality traits. Among personality dimensions, emotional stability, conscientiousness, and extraversion showed significant protective associations. Spiritual fitness dimensions revealed differential patterns: pursuing meaning, purpose, and value demonstrated significant protective effects, suggesting that active meaning-making buffers against depression. However, personal connection to a higher power showed an unexpected positive association with depressive symptoms, possibly reflecting spiritual struggles, reactive seeking during distress, or tensions navigating religious transitions in contemporary Polish society. Service orientation showed no significant direct effects. Longitudinal mediation analysis, controlling for baseline depression, revealed that positive mental health at follow-up significantly mediated the relationship between protective personality traits and depressive symptoms, accounting for 41% of personality's total protective effect. These findings demonstrate that positive mental health represents a more potent protective resource than stable personality traits and serves as a key mechanism linking personality to depression outcomes, while highlighting the complexity of spirituality-mental health relationships. Results suggest that interventions targeting modifiable positive mental health resources and meaning-making may offer efficient pathways to depression prevention.