Background:
There are little population-based data on epidemiology of psychiatric disorders in breast cancer. Since the National Health Insurance (NHI) Program in South Korea covers the whole population living in the Korea as a compulsory social insurance system, NHI of Korea can be a good information source for epidemiological study. The present study examined the incidence of psychiatric disorders among women with breast cancer in Korean population using NHI database.

Methods:
The present study used a Korea national database to examine the incidence of psychiatric disorders in breast cancer patients in Korea. We examined patients newly diagnosed with breast cancers using database from the National Health Insurance Corporation of Korea from September 2004 to August 2009 for psychiatric disorders, and September 2005 to August 2008 for breast cancer. Since the “F” at the beginning of the code indicating “psychiatric disorder”, we selected women who had F codes as a registered principal or additional diagnosis among women diagnosed with breast cancer

Results:
We identified 6,536 patients with psychiatric disorders among 42,190 women with breast cancer. The most prevalent condition of psychiatric disorders was anxiety disorder (N=2,518), followed by depressive disorders (N=2,083). The incidence rates of anxiety disorder, depression, insomnia and adjustment disorder were 27.08, 22.41, 10.57 and 4.35 cases per 1000 person-year, respectively.

Conclusions:
The incidence rates of psychiatric disorders were much lower than previous reports assessed by psychiatric interviews or screening tools. Psychiatric disorders including anxiety and depressive disorders tend to be underrecognized and undertreated among breast cancer patients. Special attention should be given for psychiatric comorbidity to women with breast cancer.