Longitudinal bidirectional association between gastrointestinal disease and depression symptoms among middle-aged and older adults in China

BACKGROUND: Longitudinal reciprocity between gastrointestinal disease (GID) and depression has not been explored among middle-aged and older adults. METHOD: This study included 12,366 participants aged 45 and above from the 2015, 2018 and 2020 survey waves of the China Health and Retirement Longitudinal Study (CHARLS) conducted in China. Depression was defined as a score of 10 or higher on the 10-item Center for Epidemiological Studies Depression Scale (CES-D-10). The GID was identified on the basis of the presence of physician-diagnosed stomach or other digestive diseases, excluding tumors or cancers. Cox proportional hazards models were used to explore the longitudinal relationship between baseline GID and subsequent depression onset, as well as the association between baseline depression and newly reported GID. To assess bidirectional associations and the strength of different directional associations simultaneously, cross-lagged panel models (CLPMs) were also employed. Stratification analyses were performed to identify vulnerable populations for each directional path. RESULTS: The baseline prevalence rates of GID and depression were 24.6% and 32.8%, respectively. Cox models revealed significant associations between baseline GID and new-onset depression (HR = 1.36, 95% CI: 1.25, 1.48) and between baseline depression and newly reported GID (HR = 1.61, 95% CI: 1.41, 1.84). After controlling for both confounders and interwave correlations, the CLPM demonstrated longitudinal bidirectional associations between GID and depression across three survey waves (P value < 0.001 for all cross-lagged coefficients) and revealed that gastrointestinal health was the stronger driving force in its dynamic interaction with depression. Females and urban residents are more susceptible to the impact of GID on depression onset, with females also being more vulnerable to depression influencing GID onset. CONCLUSION: GID may stem from worsening depression, whereas GID itself contributes to the aggravation of depression among middle-aged and older adults, suggesting that targeted interventions for either gastrointestinal health or depression may yield reciprocal benefits over time.