Abstract
OBJECTIVES: The diagnosis and treatment of cancer are stressful events that could trigger psychological distress in a large number of cancer patients. The aim of this study was to examine the association between gastric cancer and the risk of new onset of depression among South Korean adults. METHODS: Data from 12,664 participants aged over 40 years was derived from the National Health Service National Sample Cohort (2002-2013). The case cohort consists of patients who received a diagnosis of gastric cancer between 2002 and 2009, and the corresponding control group was selected through 1:1 propensity score matching (case: 6332, control: 6332). The new onset of depression was considered as the dependent variable. A Cox proportional hazards regression model was built to analyze the associations between variables in consideration. RESULTS: Individuals with gastric cancer had a higher risk of new onset of depression than those without cancer (hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.13-1.45.) Female gastric patients had a higher risk of depression compared to male patients (Female; HR = 1.89, 95% CI = 1.66-2.16, Male; HR = 1.25, 95% CI = 1.10-1.41). Gastric cancer patients in their 60s had the highest risk of new onset of depression compared to other age groups and no cancer group (HR = 1.61, 95% CI = 1.40-1.85). Gastric cancer patients who were previously diagnosed with depression prior to their diagnosis of cancer had a higher risk of new onset of depression than gastric cancer patients without antecedent diagnosis of depression (Past Depression (Yes); HR = 5.17, 95% CI = 4.10-6.51, Past Depression (No); HR = 1.35, CI = 1.21-1.51). CONCLUSIONS: The study identified a significant relationship between gastric cancer and depression among South Korean adults, suggesting that the diagnosis and treatment of gastric cancer increases the risk of new onset of depression, especially among female patients between 60 and 69 years old of high income and living in metropolitan regions. Pre-existing health conditions also appeared to be a risk factor. Thus, in consideration of treatment efficacy and patients' quality of life, the results of the study emphasizes the need for attentive intervention, while distinguishing the most vulnerable groups.