Inter- and intrapopulation differences in the association between physical multimorbidity and depressive symptoms

Area of Science:

• Gerontology
• Public Health
• Epidemiology

Background:

• Physical multimorbidity, the co-occurrence of multiple chronic conditions, presents varying associations with depression across different populations.
• Previous research has not directly compared these associations within and between populations, highlighting a gap in understanding global health disparities.

Purpose of the Study:

• To estimate the association between physical multimorbidity and depression in China and the United States.
• To reveal inter- and intrapopulation differences in this association.

Main Methods:

• Utilized data from the China Health and Retirement Longitudinal Study and the Health and Retirement Study, including middle-aged and older adults.
• Defined physical multimorbidity as two or more simultaneous chronic physical conditions.
• Employed generalized estimating equation models and stratification multilevel methods for statistical analysis.

Main Results:

• Physical multimorbidity was linked to a higher risk of depression in both China (RR=1.360) and the US (RR=1.613).
• For individuals with low multimorbidity risk, the likelihood of depression increased by 47.4% in China and 71.1% in the US.
• Cross-national differences in the association were more pronounced among individuals at high risk of multimorbidity.

Conclusions:

• Physical multimorbidity elevates depression risk in both Chinese and American adults, with a more significant impact observed in the US.
• The strength of this association varied by individual risk levels for multimorbidity.
• Substantial cross-national disparities in the depression-multimorbidity link were evident, particularly in high-risk groups.