The association between urbanization and depression in the elderly: A network analysis from the complexity science perspective

Importance: The global increase in urbanization has coincided with a rise in depression prevalence. However, the effect of urbanization on depression remains controversial, especially for the elderly. Objective: To clarify how urbanization impacts depression in the elderly from a network perspective. Design, setting, and participants: This sectional cohort study used data from China Health and Retirement Longitudinal Study (CHARLS). Main outcomes and measures: The occurrence of depressive symptoms in urban and rural elderly residents. Network metrics of depressive symptoms. Results: Of the 13,993 participants, lower incidence of depressive symptoms was observed in urban (26.3 %, 95 % CI, 24.7 %–27.8 %) than in rural (40.4 %, 95 % CI, 39.5 %–41.3 %, P < 0.0001) residents. However, higher incidence of depressive symptoms was observed in urban (26.3 %, 95 % CI, 25.2 %–28.4 %) than in rural (17.5 %, 95 % CI, 16.1 %–18.9 %, P < 0.0001) residents in a subset of 2898 pairs of participants after PSM. No difference in the network structure and metrics between urban and rural residents before (M = 0.071, p = 0.054, S = 0.037, p = 0.80) and after (M = 0.085, p = 0.133, S = 0.086, p = 0.47) PSM was detected. The networks structure revealed that negative affect was strongly connected to somatic symptoms and that the two anhedonic symptoms were also strongly connected. Conclusions: The current study indicated the homogeneity of the ultimate nature of depression between rural and urban residents from the network perspective, supporting the viewpoint that urbanization might not impose influence on depression. Further researches delving deeper into the complexity of the issue may provide new insights into our understanding of depression in an urban environment among the elderly.