Depressive disorders among patients with gastric cancer in Taiwan: a nationwide population-based study.

Background: In cancer patients, depressive disorder comorbidity is associated with greater suicide risk and poorer treatment outcomes, quality of life, and adherence to treatment. The aim of the study was to evaluate the incidence of newly-diagnosed depressive disorders after a gastric cancer diagnosis compared with a matched cohort using the National Health Insurance Research Database in Taiwan.
Methods: We conducted a retrospective cohort study of 57,506 patients (28,753 patients with gastric cancer and 28,753 matched patients) selected from the National Health Insurance Research Database. Patients were observed for a maximum of 12 years to determine the incidence of newly-diagnosed depressive disorders. Also, a Cox regression analysis which included death as an independent censor was performed to identify the potentially predictive variables for developing subsequent depressive disorders following a cancer diagnosis among the patients suffering from gastric cancer.
Results: The cumulative incidence of depressive disorders in the gastric cancer patients was significantly higher compared to those in the matched cohort (p < .001). The adjusted hazard ratio was 1.54 (95% confidence interval, CI = 1.39-1.70, P < .001) in the gastric cancer cohort compared with the matched cohort. Independent predictive variables for developing subsequent depressive disorders among the patients with gastric cancer included female sex and hypertension.
Conclusions: In the study, higher incidence of new-onset depression, being defined by the records of the diagnostic codes combining antidepressants use in a nationwide database, was noted in the gastric cancer patients compared with the matched cohort. In addition, female sex and comorbid hypertension may be predictive variables for the subsequent depression among the patients with gastric cancer. Further clinical prospective studies were necessary to confirm these findings.