Association of depression and anxiety disorder with the risk of mortality in breast cancer: A National Health Insurance Service study in Korea

To examine whether depression, anxiety disorder, and their co-occurrence would increase the risk of mortality in patients with breast cancer, and whether antidepressant treatment would reduce the same. Data were retrieved from the database of the Korean National Health Insurance Service. Of 145,251 patients diagnosed with breast cancer between 2007 and 2014, 20,870 patients diagnosed with depression or anxiety disorder one year before breast cancer diagnosis were excluded. Thus, data of 124,381 patients were included in this study. Depression and anxiety disorder were associated with an increased risk of mortality [Hazard Ratio (HR) 1.26, 95% CI 1.18–1.36; HR 1.14, 95% CI 1.08–1.22, respectively] and their co-occurrence further increased the risk (HR = 1.38, 95% CI 1.24–1.54). Antidepressant treatment was related to a reduced risk of mortality. Compared to patients without any psychiatric comorbidity with no antidepressant treatment, the mortality risk increased in patients with either psychiatric comorbidity or both, but the risk seemed to attenuate with antidepressant treatments. The current findings suggest that psychiatric comorbidities are markers of increased mortality risk in patients with breast cancer, and antidepressant treatment may attenuate the risk. This underscores the need for screening and treating depression and anxiety disorders to improve survival in patients with breast cancer.