Diagnostic Overshadowing in Psychiatric-Somatic Comorbidity: A Case for Structural Testimonial Injustice

People with mental illnesses have higher prevalence and mortality rates with regard to common somatic diseases and causes of death, such as cardio-vascular conditions or cancer. One factor contributing to this excess morbidity and mortality is the sub-standard level of physical healthcare offered to the mentally ill. In particular, they are often subject to diagnostic overshadowing: a tendency to attribute physical symptoms to a pre-existing diagnosis of mental illness. This might be seen as an unfortunate instance of epistemic bad luck, where particular features of a group of patients make a timely and correct diagnosis unlikely. While this can explain some cases of diagnostic overshadowing, I argue that in other cases, epistemic injustice is involved. Analyzing the case of diagnostic overshadowing, I distinguish two kinds of testimonial injustice. For one, there are classic cases of transactional testimonial injustice resulting from prejudices against the mentally ill. In addition, there are cases of structural testimonial injustice resulting from features of health care systems. To overcome diagnostic overshadowing, remedies on the individual as well as structural level are thus needed.