The relationship between depression and cancer is characterized by myths that may consign the cancer patient to the inevitability of depression, or preclude the physician from taking the patient's depression seriously so that effective treatments are not pursued. A common reaction by the physician considering the possibility of depression in a cancer patient is to say, “of course the patient is depressed, who wouldn't be depressed?,” and then discounting the importance of the depression or its treatment as being secondary to the ominous prognosis and risky treatment regimens the patient faces. This reaction is somewhat akin to seeing a diaphoretic patient in the emergency room who complains of crushing substernal chest pain, and saying, “Of course the patient is having a myocardial infarction. He smokes, is hypertensive, does not exercise, and has a high-fat diet. Who would not be having a myocardial infarction?,” then walking out of the emergency room without offering assistance.

The purpose of this article is to provide a framework for understanding depression in the cancer patient, how it affects the course and prognosis of the primary cancer diagnosis, the difficulties in making a diagnosis of depression in the cancer patient, and how the treatment of depression in the cancer patient differs from usual approaches. This article addresses the following four issues: