Depression and cancer mortality: a meta-analysis

Background. The goal of the present study was to analyze associations between depression and mortality of cancer patients and to test whether these associations would vary by study characteristics. Method. Meta-analysis was used for integrating the results of 105 samples derived from 76 prospective studies. Results. Depression diagnosis and higher levels of depressive symptoms predicted elevated mortality. This was true in studies that assessed depression before cancer diagnosis as well as in studies that assessed depression following cancer diagnosis. Associations between depression and mortality persisted after controlling for confounding medical variables. The depression-mortality association was weaker in studies that had longer intervals between assessments of depression and mortality, in younger samples and in studies that used the Beck Depression Inventory as compared with other depression scales. Conclusions. Screening for depression should be routinely conducted in the cancer treatment setting. Referrals to mental health specialists should be considered. Research is needed on whether the treatment of depression could, beyond enhancing quality of life, extend survival of depressed cancer patients.