Depressive symptoms trajectories and chronic lung diseases in Chinese middle-aged and older adults: a longitudinal cohort study

Background: This study aimed to identify distinct trajectories of depressive symptoms over time and examine their association with incident chronic lung diseases (CLDs) among middle-aged and older adults in China. Methods: Data were obtained from three waves of the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative longitudinal cohort of adults aged ≥45 years. Group-based trajectory modeling was used to identify depressive symptom trajectories. Multivariable logistic regression models were applied to evaluate associations between these trajectories and incident CLDs, after adjusting for demographic, behavioral, and clinical covariates. Results: A total of 8,428 participants were included in the present study with a mean age of 57.76±8.5 years, and 55.2% were female. Three distinct depressive symptom trajectories were identified: persistently low (n=2,193; 26.02%), persistently moderate (n=3,997; 47.43%), and persistently high (n=2,238; 26.55%). Compared to individuals in the persistently low trajectory group, those in the persistently moderate (OR=1.9, 95%CI: 1.49-2.42) and persistently high groups (OR=3.73, 95%CI: 2.93-4.75) had significantly increased risks of developing CLDs. These associations remained statistically significant after full adjustment, with (OR=1.80, 95%CI: 1.3-2.34) and (OR=3.49, 95%CI: 2.66-4.57), respectively. Conclusion: Persistently elevated depressive symptoms are independently associated with a higher risk of developing CLDs among middle-aged and older Chinese adults. Long-term monitoring of depressive symptom trajectories may facilitate early risk detection and guide targeted prevention strategies for CLDs.