Feeling depressed and fatigued does not increase a person's risk for cancer

Feeling depressed and fatigued does not increase a person's risk for cancer, according to a new study. Severely exhausted people, however, do engage in behavior that is associated with a higher cancer risk.

The study, published in the September 15, 2005 issue of CANCER, a peer-reviewed journal of the American Cancer Society, is the first prospective study using the "vital exhaustion" questionnaire to investigate this link.

The concept of vital exhaustion - described as feelings of excessive fatigue and lack of energy, increased irritability and a feeling of demoralization - grew out of the field of cardiology. Studies have identified vital exhaustion as a risk factor for heart attacks and death from a heart attack.

Depressive mood has also been widely blamed, at least in lay literature, as a risk factor for cancer. However, the scientific data is much more inconsistent than that for heart attacks. Two recent prospective studies failed to identify a link between depression and cancer.

Corinna Bergelt, Ph.D. of the Danish Cancer Society's Institute of Cancer Epidemiology in Copenhagen and colleagues followed 8527 people aged 21-94 years to investigate whether depressive feelings and exhaustion were risk factors for cancer, looking at all cancers combined, smoking-related cancers, alcohol-related cancers, virus and immune-related cancers, and hormone-related cancers.

The researchers did find people with high vital exhaustion scores engaged in behaviors that put them at higher cancer risk, such as tobacco consumption and low physical activity. Depite that, they found no association between the severity of vital exhaustion and an increased cancer risk. In fact, the authors actually found those at the highest end of the vital exhaustion score had a slightly decreased risk for cancer at all sites, virus and immune-related cancers, and smoking-related cancers. No significant associations were found between vital exhaustion and hormone- and alcohol-related cancers.

The authors conclude: "The results of this large, prospective, population-based study do not support the hypothesis that subclinical depressive feelings, as measured by the vital exhaustion questionnaire, increase the risk for developing cancer."