Elderly patients with cancer are far less likely to be diagnosed with depression than patients in any other age group for two primary reasons: There is an overlap between cancer symptoms/treatment side effects and the diagnostic criteria for depression, and older adults are more likely to present with anhedonic “depression without sadness,” according to Chris Nelson, PhD, Associate Attending Psychologist at Memorial Sloan Kettering Cancer Center in New York.
According to Dr. Nelson, self-report instruments tend to underestimate the severity of depressive symptoms, and many depressed older patients with cancer are completely overlooked. “There is clearly a need to better understand, quantify, and treat depression in older cancer patients,” he said at the 2017 American Psychosocial Oncology Society (APOS) Annual Conference in Orlando, Florida.1 “This represents a significant public health concern that will grow in importance as the U.S. population continues to age.”
Common symptoms of depression—fatigue, diminished concentration, thoughts of death/suicide, weight loss/gain—are confounded with side effects from cancer treatments or, potentially, the cancer itself. The literature suggests that two gateway symptoms—depressed mood and loss of interest—are most valuable in diagnosing depression in cancer, but according to Dr. Nelson, identifying these symptoms is not necessarily useful in older adults.
“The gateway questions come off the table as useful diagnostic criteria when we combine cancer and aging,” he said. “So we’ve been trying to identify additional symptoms that are useful for diagnosing depression in older adults with cancer.”
He and his colleagues conducted a study aimed at identifying the phenomenology of depression in older cancer patients and developing a set of indicators to identify, assess, and treat depression in this population. They performed a literature review and interviewed eight experts in the fields of oncology, social work, psychiatry, and psychology to assist in identifying important constructs.
Based on input from the experts and findings from the literature review, the researchers conducted qualitative interviews with 12 depressed and 12 nondepressed cancer patients older than age 70. Depressed patients were identified by referral and subsequently interviewed by the panel of experts to confirm their depression.
Major and Minor Themes
The researchers identified four major themes in distinguishing depression in older cancer patients: anhedonia, reduction in social relationships/loneliness, loss of meaning and purpose, and lack of usefulness and sense of being a burden. Four minor themes also emerged: attitude toward treatment, mood, regret and guilt, and physical symptoms and limitations.
In the patient interviews, the experience of anhedonia was nuanced and involved a lack of initiation of new activities in addition to difficulty maintaining existing activities, he reported. Another central construct, reduction in social relationships and loneliness, varied based on the range and depth of patients’ social engagement, but depressed patients tended to have limited meaningful relationships and were socially isolated and withdrawn.
Loss of meaning and purpose in life was salient in the depressed group, and they displayed an inability to adjust to their new limitations. “Patients in the nondepressed group didn’t need to be engaging in anything particularly purposeful, but what they did in the past carried over and was still important to them,” he noted. Lack of usefulness and sense of being a burden was also displayed in all depressed participants.
There was no difference between depressed and nondepressed participants in terms of their willingness to engage in treatment, but their attitude toward treatment was the nuanced difference. “The nondepressed were much more proactive regarding their treatment, whereas the depressed were resentful, angry, and upset about their treatment,” he said. Mood also varied more in the depressed group, with some patients citing worse mood in the morning, when the demands of the day were in front of them.
Both groups looked back at their lives and experienced some level of regret, but the amount of guilt experienced was the differentiating factor between the nondepressed and the depressed. “The depressed patients seemed to ruminate on their regrets, whereas the nondepressed were able to put their regrets in a tolerable perspective,” he said.
No actual difference in physical limitations was observed between the two groups, but a difference was noted in how they coped with those limitations. Two aspects of coping were deemed to be specifically useful to older cancer patients: acceptance of the limitations associated with aging; and adaptation—changing and modifying one’s lifestyle and activities—to adjust to those limitations.
Of the four major and four minor themes recognized by the researchers, only two—the major theme of anhedonia and the minor theme of mood—are identified in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria for depression. Based on their findings, the researchers conclude that the DSM-5 criteria might not apply in identification of depression in older patients with cancer. According to Dr. Nelson, a new patient-reported outcome based on these constructs may be beneficial in identifying depression. ■
Disclosure: Dr. Nelson reported no potential conflicts of interest.
1. Nelson C: Exploring the conceptualization of depression in older adults with cancer. 2017 American Psychosocial Oncology Society Annual Conference. Presented February 16, 2017.