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.
Psychiatry Advisor: Broadly, what is known about the association between depression and mortality in cancer patients?
Dr Rodin: Clinically significant depression is 2- to 3-times more common in cancer patients than in the general population. It is more likely to occur in cancer patients with more advanced disease, low social support, previous history of depression or other psychiatric illness, and more severe physical symptoms. Depression may adversely affect quality of life and adherence to treatment, and it is associated with a poorer rate of survival.
Ms Abbitt: Much of the association between mortality and depression in cancer patients is related to lack of recognition of depression symptoms. It has been shown that cancer patients with clinically identified depression have better outcomes when their depression is treated with pharmacologic or psychological support or both.
Psychiatry Advisor: What are the clinical implications of such findings?
Dr Rodin: Although it is not clear that depression treatment improves survival, the benefits in terms of quality of life and well-being of cancer patients may be profound. Psychotherapeutic and pharmacologic interventions have both been shown to relieve depression in cancer patients. Antidepressant medication may also be indicated for more severe depressive disorders. Routine distress screening to detect depression may be of value in cancer clinics to enhance detection and treatment of depression. Treatment of pain and other physical symptoms may also be important in relieving and preventing symptoms of depression.
Ms Abbitt: The most important takeaway is to be aware of the signs and symptoms of depression in cancer patients. These symptoms, such as weight loss, change in sleep patterns, loss of appetite, and lack of energy, also occur in cancer patients without depression, and thus these symptoms can be misinterpreted as only part of the course of cancer or treatment.
Psychiatry Advisor: What should be the focus of future research in this area?
Dr Rodin: More research is needed on the benefit of routine detection and treatment of depressive symptoms in cancer patients. The results have been promising thus far and suggest that more resources are needed in order for such interventions to become a more routine part of cancer care.
Ms Abbitt: Further research in this area should explore improvements in depression screening and a standardized screening procedure for cancer patients throughout the course of their disease.
- Pratt LA, Brody DJ. Depression in the U.S. household population, 2009-2012. NCHS Data Brief. 2014;(172):1-8.
- Massie MJ. Prevalence of depression in patients with cancer. J Natl Cancer Inst Monogr. 2004;(32):57-71.
- Sherrill C, Smith M, Mascoe C, Bigus E, Abbitt D. Effect of treating depressive disorders on mortality of cancer patients. Cureus. 2017;9(10):e1740.
- Sullivan DR, Forsberg CW, Ganzini L, et al. Longitudinal changes in depression symptoms and survival among patients with lung cancer: a national cohort assessment. J Clin Oncol. 2016;34(33):3984-3991.
- Giese-Davis J, Collie K, Rancourt KMS, Neri E, Kraemer HC, Spiegel D. Decrease in depression symptoms is associated with longer survival in patients with metastatic breast cancer: a secondary analysis. J Clin Oncol. 2011;29(4):413-420.
- Rieke K, Schmid KK, Lydiatt W, Houfek J, Boilesen E, Watanabe-Galloway S. Depression and survival in head and neck cancer patients. Oral Oncol. 2017;65:76-82.