Trends in self-reported lifetime diagnosed depression and health behaviours in Poland, 2019/2020–2023/2024: a repeated cross-sectional study of 1.2 million adults

Abstract

Abstract Introduction Since 2019, Poland has faced overlapping macroeconomic and geopolitical crises whose implications for population mental health remain poorly understood. This study quantifies the trajectory of lifetime diagnosed depression from 2019/2020 to 2023/2024 and concurrent shifts in health behaviours. Methods A repeated cross-sectional survey across five annual waves (2019/2020–2023/2024) was conducted among 1 196 102 Polish adults recruited through a health-focused online platform. The primary outcome was self-reported lifetime diagnosed depression; secondary measures included health behaviours such as fast-food consumption, at-risk drinking and dietary supplementation. Temporal trends and adjusted ORs (aORs) were estimated using unweighted primary data, with post-stratification weighted sensitivity analyses. Results Self-reported lifetime diagnosis of depression rose from 10.1% (2019/2020) to 18.2% (2023/2024), an increase of approximately 80%; corresponding weighted estimates were 10.2% and 20.5%. Women had consistently higher odds of depression (aOR 1.83–2.14 across waves) and prevalence was highest among the youngest adults. While reported depression rose, traditional risk behaviours declined significantly (frequent fast-food consumption 2.7% to 1.4%, a 48% decline; at-risk drinking 3.8% in 2020/2021 to 2.5% in 2023/2024, a 34% decline). Conversely, dietary supplementation was consistently associated with higher odds of depression (aOR 1.34–1.42). Conclusion The proportion of Polish adults reporting a diagnosis of depression rose by approximately 80% between the study waves. Whether this reflects a rise in incidence, improved recognition and reporting, or both, the number of adults with a depression diagnosis has grown substantially, with direct implications for service demand. This increase coincided with declines in several traditional risk behaviours, indicating that improvements in individual lifestyle indicators should not be read as evidence of improving population mental health, and underlining the need for continuous surveillance during overlapping crises.