The Prevalence and Predictors of Depression in a Community Sample of Adults with Diabetes By Income Status

Background and Purpose: Adults with diabetes are two to three times more likely to experience depression than those without diabetes. The concurrent presence of diabetes and depression is linked to negative health outcomes, including poor glycemic control, heightened risk of microvascular and macrovascular complications, increased mortality rates, and reduced quality of life. A better understanding of depression among adults with diabetes is crucial for enhancing health outcomes in this population. However, despite extensive literature on the psychosocial factors associated with depression in general, there is a notable gap in research specifically addressing these factors in adults with diabetes. This study aims to bridge this gap by analyzing psychosocial predictors of depression within a large, nationally representative sample of adults with diabetes. Additionally, the current study stratified the analysis by household income quartiles to examine the issue through the lens of social determinants of health.

Methods: Data were obtained from the 2023 Community Health Survey, a nationwide cross-sectional survey, collected by the Korea Disease Control and Prevention Agency. Using stratified multi-stage cluster sampling, a total of 231,752 respondents participated in this survey. The final sample for this study included 31,725 adults with diabetes. Depression was measured by the PHQ-9, with scores of 10 or above indicating clinically significant depression. Psychosocial predictors of depression included age, gender, marital status, education, employment status, self-reported health, stress levels, social contact, and participation in social activities. A series of logistic regression analyses were conducted, accounting for the survey's complex design.

Results: The prevalence of depression among adults with diabetes was highest in the lowest income quartile at 10.3%, decreasing progressively to 5.6% in the second quartile, 3.9% in the third quartile, and 2.7% in the highest income quartile. Across the income spectrum, marital status, self-reported health, and stress levels were consistently significant predictors of depression among adults with diabetes. However, the significance of other predictors varied by income quartile. For instance, in the lowest income quartile, both social contact (OR=.936, 95%CI=.918-.954) and participation in social activities (OR=.819, 95%CI=.744-.900) were inversely related to depression risk. In contrast, in the highest income quartile, neither factor was significantly associated with depression.

Conclusions and Implications: The literature on social determinants of health has revealed that income-related inequalities are involved in the onset and progression of diabetes. This study's findings underscore the modifying role of income on the relationship between psychosocial factors and depression risk among adults with diabetes. Perhaps income-related inequalities not only impact the occurrence and progression of diabetes but also influence the onset of depression among adults with diabetes. Healthcare providers should consider socioeconomic status when developing prevention and treatment strategies for adults with diabetes, as recognizing the influence of income on the dynamics between social factors and depression could facilitate more customized and effective care.