Association between depression and disease-specific treatment

Depression is a known risk factor for noncompliance to medical treatment. However, it remains unclear whether comorbidities alter the relationship between depression and treatment compliance. We explored whether depression is associated with disease-specific treatment service utilization.

This cross-sectional study utilized data from 499,492 individuals who had at least one comorbidity in the Korean Community Health Survey, 2009-2013. Self-reported lifetime depression diagnosis by a physician, current depressive symptoms, and utilization of medical services were queried. The association between depression status and the use of overall treatment services was investigated using multiple logistic regression models and further stratified by use of specific medical treatment under conditions predefined with the Charlson Comorbidity Index (CCI).

Compared with non-depressed people, individuals with a "lifetime history of depression with current depressive symptom" showed higher odds of using overall medical treatment services in both men (OR=1.21, 95%CI: 1.00-1.47) and women (OR=1.13, 95% CI: 1.02-1.25). However, depressed individuals with CCI comorbidities (e.g., diabetes mellitus or angina) exhibited less utilization of treatment services than non-depressed individuals.

The nature of the cross-sectional study limits the ability to infer a temporal causal relationship.

Overall, depressed individuals with a lifetime history of depression used treatment services more frequently than non-depressed individuals; however, depressed individuals with major illnesses tended to seek treatment for their medical conditions less. The mental health of patients who seek for medical services should be carefully considered in primary care for the proper health service utilization.