Cancer and depression: a concise review

Both depressive and malignant disorders are endemic, furthermore, they are also frequently comorbid. In this narrative review, we briefly discuss the epidemiological aspects of the association between depression and cancer, including the following: 1) the prevalence of depression among patients with cancer is higher than that of the general population; 2) the incidence of cancer is higher among subjects with depression; 3) depression is associated with elevated cancer-specific mortality; and 4) the suicide mortality among cancer patients. Furthermore, we also discuss the possible etiological explanations of the frequent co-occurrence of depression and malignancies, including those biological and psychological factors that may explain how depression (and/or its treatment) may lead to the development of malignancies and vice versa. Finally, some aspects of screening and treatment of depression in cancer patients are also considered. Related to this, we may state that, taking into consideration that depression is frequently underdiagnosed in cancer patients, screening is recommended in this population. However, screening for depression is valueable only if the screened patients found depressed have access to psychiatric services where the final diagnosis can be made and some kind of antidepressive treatment is available.