Depression affects approximately 7.6% of Americans aged 12 years and older, and a higher prevalence has been observed among individuals with comorbid chronic disease, including cancer.1 Because certain types of cancer are associated with higher rates of depression, the estimated prevalence of depression in a general cancer population is not well established, although some research groups estimate rates as high as 38%.2
Patients with comorbid cancer and depressive disorders have been found to have a poorer prognosis than those without depression, and delays in the diagnosis can further worsen outcomes. However, depression diagnosis in patients with cancer can be challenging due to overlapping symptoms between the two diseases, such as sleep and appetite disturbances.
A review published online in Cureus in October 2017 explored studies from 2009 to 2017 that investigated associations between depression and mortality in cancer patients.3 The authors focused on studies that examined cancer types with a higher prevalence of depression, including lung, breast, head and neck, glial, and colorectal cancers.
Selected findings are summarized below.
- In a 2016 prospective, observational study published in the Journal of Clinical Oncology, 1790 patients with lung cancer were evaluated with the Center for Epidemiologic Studies Depression Scale (CES-D) at diagnosis and 12 months later.4 Depression symptoms at follow-up were linked with increased mortality among patients with early-stage disease (hazard ratio [HR], 1.71; 95% CI: 1.27-2.31) and late-stage disease (HR, 1.32; 95% CI: 1.04-1.69).
- Patients whose depression symptoms were in remission at follow-up demonstrated mortality rates similar to patients who had never had depression symptoms. The median survival rate of these patients was 130 days longer than that seen with either new-onset or persistent depression.4 “The findings of this study suggest the potential reversibility of the effects of depression symptoms on the outcome of cancer patients,” wrote the authors of the Cureus review.3
- As reported in the Journal of Clinical Oncology in 2011, researchers conducted a secondary analysis of a randomized trial of supportive-expressive group therapy (SET) with a sample of 101 women with metastatic breast cancer.5 Their aim was to investigate the association between changes in depression symptoms as measured by the CES-D and survival time in women randomly assigned to 12 months of SET vs those in the control group, who only received educational materials regarding depression.
- According to the results, a reduction in CES-D scores over the one-year intervention period was significantly associated with longer survival times over 14 years (HR, 1.68; 95% CI: 1.16-2.45; P =.007). However, no significant interaction effect of treatment condition was found (HR, 1.48; 95% CI: 0.70-3.13; P =.30). These observations underscore “the importance of managing depression symptoms as soon as possible, as the impacts of reducing depressive symptoms are long-lasting,” the review authors stated.3
- A 2017 study assessed the effects of depression on 5-year survival rates in 3466 patients with head and neck cancer (HNC), using information from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database.6 During the study period, 18.5% of patients were diagnosed with depression. Patients who received a depression diagnosis before or after the cancer diagnosis were more likely to die from cancer (HR, 1.49; 95% CI: 1.27-1.76, and HR, 1.38; 95% CI: 1.16-1.65, respectively) compared with patients without depression.6
- In addition, compared with patients without depression, patients diagnosed with depression either before or after the cancer diagnosis were more likely to die from any cause (HR, 1.55; 95% CI: 1.36-1.76, and HR, 1.40; 95% CI: 1.21-1.62, respectively). “The results emphasize the need for early identification and treatment of depression in HNC patients, as well as the establishment of policies to routinely screen these patients throughout the cancer treatment process,” the authors of the study concluded.6
For more details regarding the connection between depression and mortality in cancer patients, Psychiatry Advisor interviewed Gary Rodin, MD, professor of psychiatry at the University of Toronto and head of the Department of Supportive Care at the Princess Margaret Cancer Centre; and Danielle Abbitt, a fourth-year medical student at the University of Central Florida College of Medicine, who co-authored the aforementioned Cureus review.
This article originally appeared on Psychiatry Advisor