The findings indicate that there are significant relationships between SES variables and prevalence of depression among older adults in rural southwest China. Further, the present study also reveals that older adults with depression have significantly lower QOL scores compared to those without depression.
The prevalence of depression was higher in the present study than in the WHO-SAGE survey results of China (2.6%), Ghana (11.0%), South Africa (6.4%),[21] and Sweden (5.9%),[22] but lower than of? India (27.4%), Mexico (23.7%), Russia (15.6%),[21] and Brazil (30.2%).[23] It was also lower than that found in a meta-analysis of Chinese studies from 1987 to 2012 (23.6%).[24] Furthermore, females in the present study had a higher prevalence of depression than males, a finding in line with previous research.[25-26] This gender disparity may result both from biological factors, as sex hormones play an important role in occurrence of depression,[27] as well as environmental factors. Specifically, women in rural China commonly engage in heavy physical labor, suffer from social injustices, and have a widowed rate that increases with life expectancy, all key factors that could impact their mental health status.[28] The findings thus suggest future community-based depression prevention and intervention efforts should pay particular attention to female older adults.
The present study also indicated that older adults who live alone are more likely to develop depression compared to those living with a spouse and/or with their children. This is consistent with previous research and possibly results from the fact that living with family may provide psychological safety and sense of belonging, which has a positive effect on depression.[29] Moreover, spousal support and family support were associated with protection from depression, an association particularly salient for older adults.[30]
While previous studies demonstrated those with lower levels of education had a higher likelihood of suffering from depression,[31-33] the present study found no association between educational level and depression. Further investigation is needed to examine the exact nature of the association between education and depression.
The present study did however align with previous research demonstrating lower household income is associated with higher risk of depression.[33] Furthermore, the present study also found older adults with poor access to medical services are more likely to be depressive. This may be attributed to disadvantages in conditions and healthcare access in rural regions compared with urban ones.[34] Poor access to medical services can cause or aggravate poor physical health, which in turn can influence mental health status and make depressive symptoms worse.
Our study additionally found that depression had a significant impact on older adults’ QOL, with depressive older adults achieving significantly lower scores on all domains of QOL compared to those without depression. This result accords with previous research[14, 35].These negative correlations between depression and dimensions of PCS and MCS remained after adjusting for possible confounders, which also showed significant differences in the univariate analysis. These findings underscore the importance of taking measures to improve mental health in order to optimize QOL among the rural elderly.
The present study was limited by the following factors. Firstly, the prevalence of depression was based on self-assessment using GDS-30, and the lack of validation of clinical diagnosis for depressive status may have underestimated the prevalence of depression and thereby affected the accuracy of the rates of depressive status recorded. Secondly, the data analyzed in this study was cross-sectional, so causal relationships could not be determined.
In conclusion, based on the finding that individual SES has a significant impact on prevalence of depression, future interventions to reduce prevalence of depression should focus on female, low-income, older adults, as well as older adults with poor access to medical services. These findings additionally underscore the importance of improved mental health among older adults in order to optimize QOL.