Sleep Quality, Stress, and Mental Health in College Students: The Protective Role of Optimism and Critical Thinking

Mental health among university students is an issue of growing global concern, impacting both psychological well-being and academic outcomes. This study investigated the relationships between sleep quality, perceived stress, anxiety, and depression, examining the mediating role of perceived stress and the protective effects of optimism and critical thinking. A sample of 363 Italian university students (mean age = 22.67 ± 4.64 years) completed standardized self-report questionnaires assessing the main psychological variables of interest. Data were analyzed using structural equation modeling (SEM) with bootstrapping to evaluate mediating and moderating effects. SEM analyses showed that perceived stress partially mediated the effect of sleep disturbances on anxiety (β = 0.27, 95% CI 0.18, 0.37) and depression (β = 0.24, 95% CI 0.16, 0.33). Moreover, the impact of sleep problems on perceived stress was attenuated among students with higher levels of optimism (β = −0.18, p = 0.003) and critical thinking (β = −0.14, p = 0.01), confirming the protective role of these personal resources. These findings highlight the importance of considering both risk factors and protective resources in understanding and preventing psychological distress in university populations, suggesting interventions aimed at improving sleep quality and enhancing individual resources.