We conducted three surveys on representative random samples of adult Polish residents drawn from the citizens' register. They were conducted in June 2022 ( = 1050), October 2022 ( = 1041), and February 2023 ( = 982). Interviews were conducted using a mixed-mode technique (CAPI, CATI, and CAWI). Our key findings are that at least mild symptoms of depression are exhibited by a quarter of adults surveyed (25.8%), including a tenth (9.4%) with moderate or more severe symptoms. Translated to the population, that is more than 7.5 million Poles with at least mild symptoms and more than 2.7 million with more severe symptoms, respectively. The scale of depression symptoms is characterized by a certain seasonality. Fewer people experience them in spring than in autumn and winter. The most significant risk factors include, first of all, a poor economic situation, the presence of other health problems, and young age. There is also a higher risk for women and residents of large cities.