Mood Changes and Advanced Breast Cancer Treatment

Reviewed by: HU Medical Review Board | Last reviewed: June 2023

Dealing with a diagnosis of and treatment for advanced breast cancer can be incredibly stressful and can cause a lot of mental and emotional strain. In addition, the treatments for breast cancer may also cause mood changes. Some people with breast cancer may experience clinical depression or anxiety, and studies have found that depression may be misdiagnosed and undertreated in women with breast cancer.1

Mood changes can potentially be worsened by fatigue or pain. Fatigue is a common side effect of treatment for breast cancer and can complicate depression. Depression can also cause fatigue, so someone who is experiencing both may need a multi-faceted approach to managing these symptoms. Pain can be caused by advanced breast cancer or as a side effect of treatment, and pain can have a major impact on a person’s quality of life, including increasing the potential for and worsening mood disorders like depression.2


Depression is a condition that affects how a person thinks and feels, as well as impacting their daily activities such as sleeping or eating. Also referred to as major depressive disorder or clinical depression, common symptoms may include:3

  • Feelings of sadness, hopelessness or an empty mood
  • Moodiness or irritability
  • Feelings of worthlessness or helplessness
  • Fatigue or decreased energy
  • Challenges with concentrating or focusing
  • Loss of interest in activities that used to bring joy
  • Difficulty making decisions
  • Difficulty with falling asleep, staying asleep, or sleeping more than usual
  • Changes in appetite, which may range from a loss of appetite to an overactive appetite
  • Aches or pains without a clear cause
  • Thoughts of death or suicide

Not everyone with depression will necessarily experience all of these symptoms, and the symptoms of depression can vary between patients. Symptoms may vary in severity among different individuals, too.3

Depression and breast cancer

Major depressive disorder is estimated to occur in about 3.5-7% of all women in the general public. This estimate goes up when looking at women with breast cancer, with an estimated 10-25% of women with breast cancer experiencing depression. Rates of depression appear to be higher in the first year following diagnosis and in women treated with chemotherapy.4

Treating depression in women with breast cancer can improve quality of life and may also increase longevity. Certain antidepressants may also have other benefits, such as potentially lessening hot flashes caused by hormone therapies or treatment-induced menopause.1,4


Most people occasionally feel anxious. However, anxiety disorders cause a persistent and/or excessive level of anxiety or worry. Common symptoms of generalized anxiety disorder include5,6:

  • Feeling restless, wound up, irritable, or on-edge
  • Feeling easily fatigued
  • Having difficulty focusing or concentrating
  • Having increased muscle tension
  • Having difficulty controlling worrying thoughts
  • Experiencing sleep problems, such as difficulty falling asleep, restless sleep, or trouble staying asleep
  • Rapid heartbeat
  • Shortness of breath or tightness in the chest
  • Digestive symptoms, such as nausea, vomiting, or diarrhea
  • Needing to urinate frequently

Anxiety and breast cancer

Research has suggested that as many as 77% of cancer patients experience anxiety within two years of treatment. While in many people, anxiety is a natural and common reaction to a cancer diagnosis, some people experience anxiety that impacts their lives in negative ways. The levels of anxiety can vary among different individuals and can increase during certain times, such as waiting for test results or learning that breast cancer has spread.6

Getting help

Women with advanced breast cancer who are experiencing symptoms of mood changes such as those associated with depression or anxiety can benefit from getting help. Treatment may include counseling, medications, or a combination of both. Treating anxiety and depression can improve a person’s quality of life, potentially reduce overall fatigue and pain, and may potentially improve a person’s response to treatment for breast cancer.4,6

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