Mental Health and Cancer Mortality

What does research show about psychological distress and cancer mortality?

An important foundation for this research is a 2017 BMJ analysis combining 16 prospective cohort studies. It followed 163,363 people who had no cancer diagnosis at enrollment for an average of 9.5 years. Participants reporting higher psychological distress subsequently experienced higher mortality from cancer overall. These are established findings, rather than newly released results. [BMJ study](https://www.bmj.com/content/356/bmj.j108)

The population studied matters: this was not simply an investigation of depression among people already receiving cancer treatment. Cancer mortality in an initially cancer-free population reflects both the likelihood of developing cancer and survival after diagnosis. The findings therefore cannot tell an individual patient how their emotional state will affect their prognosis. Nor did the study test whether treating distress prevents cancer deaths. [Study abstract](https://pubmed.ncbi.nlm.nih.gov/28122812/)

Does stress directly cause cancer to progress?

Stress activates hormonal responses that can affect many tissues. According to the National Cancer Institute, experiments involving animals and cancer cells suggest that stress-related signaling may influence tumor growth, blood vessel formation and immune activity. However, laboratory mechanisms do not establish that everyday worry causes a person's cancer to worsen. [National Cancer Institute: Stress and Cancer](https://www.cancer.gov/about-cancer/coping/feelings/stress-fact-sheet)

Human studies are harder to interpret because distress overlaps with physical illness, health behaviors and other circumstances. The National Cancer Institute describes the overall evidence that stress directly affects cancer survival as weak. Patients should not interpret an association as evidence that they caused their illness or must maintain a positive outlook to recover. Mental health care deserves attention because suffering and quality of life matter, even when a survival benefit remains unproven. [National Cancer Institute: Stress and Cancer](https://www.cancer.gov/about-cancer/coping/feelings/stress-fact-sheet)

How should depression be addressed during cancer treatment?

Depression can involve ongoing sadness, loss of interest, hopelessness and difficulty functioning. Assessment during cancer treatment requires care because fatigue, poor sleep and appetite changes can also reflect the disease, medication effects or other medical problems. The National Cancer Institute recommends discussing symptoms, their duration and their impact with the health care team; examination or laboratory testing may help identify contributing conditions. [National Cancer Institute: Depression](https://www.cancer.gov/about-cancer/coping/feelings/depression-pdq)

Treatment may include psychotherapy, medication or both, selected according to symptoms and the patient's medical circumstances. A useful conversation begins with concrete changes: difficulty getting through the day, withdrawing from enjoyable activities or feeling unable to continue treatment. These concerns warrant clinical attention rather than an assumption that depression is inevitable after diagnosis. [National Cancer Institute: Depression](https://www.cancer.gov/about-cancer/coping/feelings/depression-pdq)