Sociodemographic, Lifestyle, and Work-Related Correlates of Mental Health Outcomes: A Large-Scale Cross-Sectional Web-Based Study of 1.19 Million Adults in Poland (2020–2024)

Background Mental health represents a growing public health challenge, exacerbated by recent global and regional crises. This study aimed to identify sociodemographic, lifestyle, and health-related correlates of key mental health outcomes - primarily depression, insomnia, and job burnout - in a large sample of adult internet users in Poland. Methods We analyzed pooled cross-sectional data from 1 196 102 adults participating in an annual web-based health survey in Poland between 2020 and 2024. Ordinal and binary logistic regression models were used to assess associations between predictors (sociodemographics, lifestyle factors, chronic diseases, stress, social relationships) and self-reported mental health outcomes. Neurological diseases, memory disorders, and frequent headaches were also assessed as secondary outcomes. Results Significant gender disparities were observed, with women reporting higher odds of depression, insomnia, and job burnout (p < 0.001). Daily stress and low social support were the strongest correlates, heavily associated with increased odds of all adverse mental health outcomes (p < 0.001). The presence of chronic diseases (particularly arthritis and heart disease) and specific lifestyle factors (e.g., lack of physical activity, smoking) were also significantly associated factors. Conversely, regular physical activity and frequent social contact were protective. Conclusions Mental health outcomes among Polish adult internet users are strongly associated with a complex interplay of psychosocial, health, and lifestyle factors. High stress, poor social support, and chronic illness burden are major correlates of poor mental health. These findings emphasize the need for targeted, broad-based public health interventions promoting stress management and social connection.