Sontag begins Chapter 7 by disentangling two often tangled elements: depression and cancer. She mentions some contemporary medical studies that report cancer patients having suffered from depression and trauma. Depression, she is quick to point out, is part of the human condition and affects most people independent of any diagnosis. Feelings of isolation and despair have not always been associated with cancer diagnosis, although they are more frequent in the 20th-century American context.

These trends indicate a connection between victimhood and psychological traits. For example, according to the ancient Greek physician Galen, melancholic women were more susceptible to breast cancer than sanguine women. The association between psychology and diagnosis hardly changed over centuries: In 1845, the surgeon Sir Astley Cooper reported that anxiety and grief were the most common causes of breast cancer. Sontag is quick to note that while the personality and psychological traits connected to cancer have changed over time, that line of thinking should not be conflated with the idea that depression or distress can lessen immunological responsiveness.

What all these examples amount to for Sontag is that a conflation of psychology and disease is proof of a lack of medical knowledge. It is both an ancient and a modern predilection.