Depression can affect a cancer patient’s likelihood of survival, according to University of British Columbia researchers who have conducted the world’s first analysis of existing cancer and depression research.
A number of studies have shown that individuals’ mental attitudes can impact their physical health. To determine the effects of depression on cancer patients’ disease progression and survival, UBC Dept. of Psychology graduate student Jillian Satin and colleagues analyzed all studies to date that they could identify related to the topic.
The researchers found 26 studies with a total of 9,417 patients that examined the effects of depression on patients’ cancer progression and survival. Their analysis is published online today by the American Cancer Society journal Cancer.
“We found an increased risk of death in patients who report more depressive symptoms than others and also in patients who have been diagnosed with a depressive disorder compared to patients who have not,” said Satin. In the combined studies, the death rates were as much as 25 per cent higher in patients experiencing depressive symptoms and 39 per cent higher in patients diagnosed with major or minor depression.
The increased risks remained even after considering other clinical characteristics that might affect survival, indicating that depression may actually play a part in shortening survival. However, the authors say additional research must be conducted before any conclusions can be reached. The authors add that their analysis combined results across different tumor types, so future studies should look at the effects of depression on specific kinds of cancer.
The investigators note that the actual risk of death associated with depression in cancer patients is still small, so patients should not feel that they must maintain a positive attitude to beat their disease. Nevertheless, the study indicates that it is important for physicians to regularly screen cancer patients for depression and to provide appropriate treatments.
The researchers did not find a clear association between depression and cancer progression, although only three studies were available for analysis.
View Satin’s study online at www.cancer.org. Her study will appear in the print edition of Cancer on November 15, 2009.