Mental Disorders and Suicide Risk among Cancer Patients: A Nationwide Cohort Study

Abstract

Although cancer patients are known to experience mental disorders and face suicide risk, little is known about the relationship between mental illness and death by suicide in this group. As such, this study aims to examine the association between mental disorders and suicide risk among cancer patients. We used nationally representative cohort data, and included newly diagnosed cancer patients from 2004 to 2012 with whom we followed-up throughout 2013. We used the clinical diagnoses of all mental disorders as an independent variable and suicide death as a dependent variable to estimate the adjusted hazard ratio (AHR) of suicide deaths in patients with cancer using a Cox proportional hazard model. Among total cancer patients (n = 36,220), the 10,567 patients with mental disorders showed higher suicide risk than non-cancer patients (AHR, 1.53; 95% confidence interval [CI], 1.07–2.17), particularly in those who experienced mental disorders prior to cancer diagnosis (AHR, 2.24; 95% CI, 1.35–3.71). Suicide risk among cancer patients who had mood disorders (AHR, 2.23, 95% CI, 1.31–3.81) or anxiety and somatoform disorders (AHR, 1.61, 95% CI, 1.02–2.55) was higher than for those without mental disorders. Suicide risk of stomach (AHR, 3.32; 95% CI, 1.36–8.10) and liver (AHR, 7.57; 95% CI, 1.86–30.72) cancer patients who had mental disorders was higher than for patients without mental disorders. Cancer patients with mental disorders are at increased risk for suicide. During follow-ups after cancer diagnosis, early mental health support needs were provided to patients with mental disorders.

Keywords:

• Cancer
• longitudinal cohort study
• mental disorders
• suicide

DISCLOSURE STATEMENT

The authors declare that they have no conflicts of interest.

DATA AVAILABILITY STATEMENT

The National Health Service System in South Korea requires all related researchers to pledge not to release, share, or review the data. Any request regarding data and the study itself should be directed to the corresponding authors, who have signed the data release agreement form of the National Health Service System in South Korea. It is possible for other researchers to request access to the data directly from the National Health Insurance System.

Additional information

Funding

This work was supported by the National Research Foundation of Korea [grant number: 2019R1A2C1003259], the Yonsei University Research Fund (Post Doc. Researcher Supporting Program) of 2019 [grant number: 2019-12-0129], and the National Research Foundation of Korea [grant number: 2020R1I1A1A01053104].

Notes on contributors

Jae Woo Choi

Jae Woo Choi, College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea.

Eun-Cheol Park

Eun-Cheol Park, Division of Medical Science Research Affairs & President, University-Industry Foundation of Yonsei University Health System, Seoul, South Korea; Department of Preventive Medicine & Director, Insititute of Health Services Research, Yonsei University College of Medicine, Seoul, South Korea.

Tae Hyun Kim

Tae Hyun Kim, Department of Hospital Administration, Graduate School of Public Health, Yonsei University, Seoul, South Korea.

Euna Han

Euna Han, College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea.