Researchers reviewed the medical records of over 77,000 breast cancer patients and followed them until the end of 2010. Over 420 women had a history of depression prior to a breast cancer diagnosis, and 503 were diagnosed with depression after the breast cancer diagnosis.
Women with depression had a 45 percent higher risk of death from all causes, compared to those who did not.
Five years after being diagnosed, 55 percent of women with a history of depression were alive compared to 75 percent of those who were never diagnosed with depression.
Depression can also cause poor lifestyle behaviors that can contribute to a greater risk of death, such as chronic stress, unwillingness to comply with treatment and less adherence to a healthy lifestyle.
Dr. Davies concluded, “Greater social support or psychological interventions for women with breast cancer could help to reduce the negative effects amongst those most at risk of depression.”
The findings were published in Psycho-Oncology.