Comparison of depressive symptoms and sociodemographic, economic, and modifiable lifestyle correlates across age groups in the U.S. population before vs. after COVID-19 pandemic.

The COVID-19 pandemic profoundly disrupted daily life, amplifying existing stressors and introducing new challenges that potentially reshaped patterns of depression. While prior research has identified key correlates of depressive symptoms, it remains unclear how these associations may have shifted in the post-pandemic era across different age groups. Thus, this study examined changes in depressive symptom levels and their sociodemographic, economic, and behavioral correlates before and after the pandemic across different adult age groups in the United States. Data were drawn from two cycles of the National Health and Nutrition Examination Survey (NHANES): 2017-2018 (pre-pandemic; n = 3904) and 2021-2023 (post-pandemic; n = 4181). Hierarchical multivariate regression analyses assessed pre-vs. post-pandemic differences in depressive symptoms and shifts in their associations with sociodemographic, economic, and lifestyle factors. Depressive symptoms were significantly higher post-pandemic across nearly all age groups, with the largest elevations observed among young adults in their 20s (B = 2.285, p < .001, CI 95% = 1.715, 2.856), middle-aged adults in their 30s (B = 1.726, p < .001, CI 95% = 1.218, 2.234), and 40s (B = 0.751, p = .005, CI 95% = 0.222, 1.281). Clinically significant depressive symptoms more than doubled among individuals in their 20s, rising from 3% pre-pandemic to 8% post-pandemic. In contrast, symptom levels among adults aged 70 years and older remained relatively stable (B = 0.389, p = .062, CI 95% = -0.019, .797). While traditional corralates-gender, socioeconomic status, and social relationships-remained important, their relevance shifted markedly in the post-pandemic period. Economic hardship became a universal determinant of depressive symptoms, surpassing race/ethnicity, while gender became more strongly associated in midlife, and social disconnection gained even more relevance for older adults. Behavioral and structural factors, including sedentary lifestyle and lower educational attainment, also became more broadly correlated across adulthood. These findings highlight the long-term psychological impact of the pandemic and reveal a reconfiguration of depression correlates in the post-pandemic era, emphasizing the need for age-, gender-, and socioeconomic-sensitive public health interventions.