That cancer is associated with depression seems obvious at first glance. However, depression should not be ignored in cancer treatment as well, and may even have a negative impact on prognosis. The best way to interrupt this vicious cycle is not yet well understood, and with effective treatment and open communication, clinicians may be able to help patients improve their prognosis.
The following are ten facts about cancer and depression.
1. Depression can reduce survival rates in cancer patients
A study that included 217 patients with metastatic renal cell carcinoma showed that patients with depressive symptoms had a significantly lower survival rate than those who did not have similar symptoms. Twenty-three percent of patients in the study experienced clinically significant depression, and Cox regression models showed that these symptoms were associated with decreased survival (HR=1.5, 95% CI, 1.00-2.23; P=.05); at the same time, patients with impaired cortisol secretion rhythm also had lower survival (HR=1.9; 95% CI, 1.27-2.97; P=.002).
2. Depressive symptoms in cancer patients are often unrecognized
According to the National Cancer Institute, as many as 25% of cancer patients experience depressive symptoms at some point in their treatment, but they are often unrecognized. This condition may occur because patients are embarrassed to be in a depressed state or physicians are uncomfortable diagnosing psychiatric problems. In addition, depressive symptoms overlap with several side effects of cancer treatment, including fatigue, difficulty sleeping, decreased appetite, and impaired cognition, which also pose challenges in identifying depressive symptoms.
3. Depressive symptoms may vary depending on the period of cancer
The period of cancer can moderate or intensify depressive symptoms. In one study, cancer-related risk factors for depression included: diagnosis of cancer, poor pain control, cancer progression, physical impairment and pain exacerbation, pancreatic cancer, unmarried, and head and neck cancer; non-cancer-related risk factors included: history of depression, lack of family support, life stress, family history of depression, previous suicide attempts, and history of alcohol and drug abuse.
4. Patients with head and neck cancer have the highest risk of depression
Patients with head and neck cancer, especially those who are unmarried, are at high risk of depression. However, a recent study showed that taking the SSRI drug citalopram before anticancer treatment reduced depressive symptoms in these patients. The dose of citalopram in the study was 40 mg/d, and treatment lasted 12 weeks. At the end of the study, only 17% of patients in the citalopram group had depressive symptoms, compared with 50% in the placebo group; no one in the citalopram group had suicidal intent, compared with two in the placebo group.
5. Coexistence of shorter telomeres and depressive symptoms increases the risk of death by 2-fold in bladder cancer patients
In a study published in 2012, researchers enrolled 464 bladder cancer patients with a median follow-up period of 21.6 months and 88 deaths. Results showed that a score of ≥16 on the Center for Epidemiologic Studies Depression Scale (CES-D) increased the risk of death by 89% (95% CI, 1.12-3.2), and longer telomeres were associated with longer survival (HR=0.55; 95% CI, 0.34-0.89); the increased risk of death was more pronounced when depression coexisted with shorter telomeres compared with patients without depressive symptoms and longer telomeres (HR =3.19; 95% CI, 1.44-7.04) and shorter disease-free survival (DFS) (31.3 months vs. 199.8 months; P<.001).
6. Pediatric cancer patients also suffer from anxiety and depression as the saying goes, “Teenagers don’t know what it’s like to be a teenager”.
However, cancer treatment is a challenge at any age, and even children are not immune. A nationwide study shows that in addition to the cancer diagnosis itself, children feel stressed about scarring, hair loss and other disfiguring changes that occur during treatment. For example, hair loss increased the risk of anxiety (RR=1.60; 95% CI, 1.23-2.07), and changes in head and neck appearance increased the risk of depression (RR=1.19; 95% CI, 1.01-1.41).
7. Antidepressant treatment does not improve lung cancer prognosis
Despite a proven association between depression and metastatic lung cancer, a study showed that antidepressants and psychiatric visits did not provide a survival benefit for patients with this type of cancer. A total of 151 patients with non-small cell lung cancer (NSCLC) were included in the study, 21 of whom had more severe depressive symptoms. After receiving the above intervention, these patients’ PHQ-9 scores decreased significantly; however, the change in scores did not correlate with improved survival.
8. Socioeconomic status is associated with depression and anxiety in breast cancer patients
A study published in 2010 showed that for the 487 patients with intraductal breast cancer in situ included in the study, patients were more likely to have symptoms of depression (P=.0006) and anxiety (P=.0005) if they had lower socioeconomic status, a trend that was not associated with social support. The investigators also found that the educational level of these patients did not correlate with depression and anxiety.
9. Telephone counseling may improve depression and pain in cancer patients
A study showed that a telephone counseling management program and an automated home symptom monitoring system significantly improved pain and depression symptoms in cancer patients. A total of 405 subjects were enrolled in the study, of whom 131 had depressive symptoms, 96 had pain symptoms, and 178 had both symptoms. The primary endpoint of the study was the severity of depression and pain symptoms at baseline versus months 1, 3, 6, and 12. The results showed that the above interventions were effective in improving both types of symptoms.
10. It is important to ask cancer patients about their suicidal intentions
Some clinicians advocate the use of the term “psycho-oncology”, which means studying the psychological effects of cancer on patients. The risk of suicide in cancer patients (31.4/100,000) is twice as high as in the general population (16.7/100,000), and depression appears to be an important marker in determining the likelihood of suicide in patients. In addition, survivors of childhood cancer have a high risk of suicide in adulthood, even if many years have passed since treatment. In any case, it is imperative to ask about the mental status and suicidal thoughts of this group.