O ur prejudices may be leading us to the wrong diagnoses. This holiday season is a time for us to reflect on our practices and renew our efforts to look out for the vulnerable.Physicians are skilled at looking inside the body in a sensible and systematic way, and arriving at a diagnosis. In certain contexts, however, our diagnostic sensitivity may be diminished by other underlying factors, a situation known as "diagnostic overshadowing." This refers to the misattribution of physical symptoms to a pre-existing mental illness, or intellectual or developmental disability, and is often viewed as a form of bias and discrimination.1 The concept of diagnostic overshadowing is being used more widely today to indicate the overattribution of symptoms to any underlying or chronic condition, resulting in missed diagnoses and improper management of conditions. This is especially problematic in people with mental illness, because they have higher rates of morbidity and shorter life spans than the general population.