Psychological Capital and Mental Health in Ecuadorian University Students: The Mediating Role of Negative Stress

This study examined the mediating role of negative stress in the relationship between Psychological Capital (PsyCap) and psychological distress indicators among Ecuadorian university students. PsyCap was conceptualized as a higher-order construct composed of hope, self-efficacy, resilience, and optimism. A cross-sectional study was conducted with 1732 university students (55% women; M = 20.44, SD = 2.29) from three Ecuadorian universities using validated self-report measures. Structural equation modeling supported the proposed mediational model and demonstrated an adequate fit to the data, χ2(367) = 1732, p < 0.001, CFI = 0.972, TLI = 0.969, RMSEA = 0.061 (90% CI 0.058, 0.063), and SRMR = 0.041. PsyCap showed a significant negative association with negative stress (β = −0.311, p < 0.001). In turn, negative stress was positively associated with anxiety–depression symptoms (β = 0.785, p < 0.001) and psychological inflexibility (β = 0.774, p < 0.001). Mediation analyses revealed significant indirect effects of PsyCap on anxiety–depression (β = −0.244, p < 0.001) and psychological inflexibility (β = −0.241, p < 0.001) through negative stress. Direct effects remained significant but smaller in magnitude (β = −0.131 and β = −0.107, respectively), supporting a partial mediation model. The model explained 69.7% of the variance in anxiety–depression and 66.3% of the variance in psychological inflexibility. These findings suggest that PsyCap functions primarily as a protective psychological resource through its capacity to reduce maladaptive stress responses, which subsequently influence broader transdiagnostic indicators of psychological distress. The study highlights the relevance of integrating strengths-based approaches and stress-reduction strategies in university mental health interventions. Furthermore, it provides empirical evidence from a Latin American context, contributing to the understanding of mechanisms linking positive psychological resources and mental health among university students.