“Depression can get in the way of compliance with treatment,” says Susan Hedlund, LCSW, director of oncology patient and family services at the Oregon Health and Sciences University (OHSU) Knight Cancer Institute in Portland. “Meaning, if you are really depressed, you may miss appointments and scheduled medications.” Depression can also affect your relationships with family, friends, and your partner, so treating it is vital to preserving your quality of life. And Hedlund says, “We know that if the depression goes on long enough, it can change the neurochemistry of the brain, making it harder to pull out of it.” Read on to learn why the brain responds to chemotherapy this way and what you can do to manage your mood while undergoing treatment.

This Is Your Brain on Chemotherapy

Scientists suspect that chemotherapy can bring about depression in a few ways. For one, the authors of a review published in Oncology Letters suspect that haloperidol, a drug sometimes prescribed to cancer patients to help with chemotherapy-related nausea, can cause a dopamine imbalance in the brain, which can cause depression. The authors of the review also think that some chemotherapy drugs themselves can cause an inflammatory response in the body that is similar to the one stress and anxiety can cause. This response releases certain proteins, called cytokines, which signal to the body to release hormones that are associated with depression. These cytokines can also interrupt an important process in the brain called neurogenesis. Neurogenesis is the brain’s ability to generate new neurons. A study published in 2017 in Translational Psychiatry confirmed that some chemotherapy treatments can interrupt neurogenesis. Plus, the authors of review published in 2017 in Brain Research think that dysfunctional or weak connections between neurons can lead to mood and psychological disorders.

Whether you’re experiencing depression from chemotherapy or from coping with your cancer, it’s not surprising that you might be at risk of suicide. An analysis published in March 2022 in Nature Medicine showed that suicide rates were 85 percent higher among people with cancer than in the general population — and the worse the prognosis, the higher the likelihood of suicidal ideation. Another study in Nature Medicine, published the same month, showed that roughly 5 percent of cancer patients were diagnosed with depression after their cancer diagnosis. And according to a study published in 2021 in Cancer Reports, COVID-19 also made matters worse for cancer patients, who experienced elevated anxiety and depression levels during the pandemic. “It’s been so much harder during COVID,” Hedlund says. “People were so isolated, and that can contribute to not only depression but also loneliness.”

When It’s Time to Seek Help

While interrupted sleep, a loss of appetite, and frequent thoughts of death may be a sign of depression in an otherwise healthy person, Hedlund says that those indicators don’t necessarily apply to someone with cancer. “People with cancer often experience sleep and appetite disturbances and often think about death,” she says. Instead, Hedlund says to seek professional help if you find you are in a low mood most days or more days than not, and if it persists for more than three weeks. “Then it might be worth trying to get professional help, either through counseling or a combination of counseling and medication.” According to Hedlund, people with cancer-related depression might also have trouble cheering up. “Your loved ones may be really trying, but you may find that you are not affected by it if you are really depressed.” Also, people with cancer- or chemotherapy-related depression often struggle to feel joy. “Even people on chemo can say they love when their grandkids come over or love taking their dog for a walk,” says Hedlund. “If not, that’s a good indicator that you could be depressed.”

Managing Your Mental Well-Being

The results of a clinical trial published in BMC Psychiatry earlier this year showed that cognitive behavioral therapy (CBT) can help alleviate depression, anxiety, and stress-related psychiatric symptoms, such as poor sleep, among cancer patients undergoing chemotherapy. The study also shows that CBT can improve a patient’s quality of life and level of self-esteem. In addition to therapy, there are a few things you can do to help manage your mental health. First, Hedlund recommends paying attention to your diet, activity, and sleep. “Keeping a healthy sleep regimen is good. So is trying to stay active,” she says. “We used to tell people with chemotherapy-related fatigue to rest, but now we know it’s really the opposite that they need. Even just walking around the block or getting outside can have major mental health benefits.” Often, anxiety accompanies depression. “One of the things that happens when we are anxious is we are worried about the future or ruminating on the past, which can take us out of the present,” Hedlund explains. She recommends relaxation in the form of meditation, yoga, or writing. “During COVID, we saw a 250 percent increase in the number of apps available on your phone for mental health — Headspace, Calm, and UCLA even has an app. And they’re all free.” Just 10 minutes in the morning and 10 in the evening can teach vital self-soothing techniques. “And the more we do it, the better we get at it. People really describe an increased sense of well-being with those.” Reducing a sense of isolation can also help stabilize your mood. “We have three writing groups in our program at OHSU,” Hedlund says, “and we have learned that if you talk about something difficult, that’s helpful, but if you write and talk about it, that sort of shifts it so it doesn’t feel as dramatic.” She recommends finding a group, whether it be for writing, meditation, or just general support. Organizations like the Cancer Support Community offer free counseling for patients struggling with depression and other mental health concerns. “The thing I try to say to my patients is to give yourself a lot of grace. Cancer is really scary. There is a lot of grief and sadness and fear,” says Hedlund. “Usually, it gets better, but I think people expect themselves to do everything they did before and add cancer and treatment into the mix, and I think we have to give ourselves a chance to navigate the experience. It will take time to know what will work for you.”