Incidence and risk factors for psychiatric comorbidity among people newly diagnosed with cancer based on Korean national registry data

Objective: The present study investigates the incidence of psychiatric disorders, related risk factors, and the use of mental health services among people newly diagnosed with one of five major cancers (stomach, liver, colorectal, lung, and breast cancer) based on national registry data from the National Health Insurance Service (NHIS) in the Korean population. Methods: We collected data on people newly diagnosed with one of the five major cancers between 2005 and 2008 using the nationwide claims data and cancer registration files of the NHIS. We analyzed the data of those diagnosed with psychiatric disorders over a 5-year period, from 2004 to 2009. Results: Among 302 844 people with newly diagnosed cancer, we identified 31 579 patients (10.43%) who were also newly diagnosed with psychiatric disorders after their cancer diagnosis. Among psychiatric diagnoses, anxiety disorders and depression showed the highest incidences of 18.13 and 13.16 per 1000 person-years, respectively. Among major cancers, patients with lung cancer showed the highest incidence of psychiatric disorders. Older age and female gender were shown to be risk factors associated with psychiatric comorbidity, and no significant differences were found for region of residence. Conclusion: The present study showed a low incidence of psychiatric comorbidity and suggests that psychiatric disorders in cancer patients tend to be underrecognized in actual clinical practice. Greater risk for psychiatric comorbidity was associated with lung cancer, older age, and female gender. The present findings provide important information for establishing national policies to detect and manage mental health problems during cancer care. Copyright (C) 2015 John Wiley & Sons, Ltd.