'Diagnostic overshadowing': worse physical health care for people with mental illness.

It is now well established that people with mental illness die prematurely and have significantly higher medical co-morbidity compared with the general population (1), and that there are a number of possible reasons for this as discussed by Leucht et al. in the November issue 2007 of the Acta Psychiatrica Scandinavica (2). One of these may be Ôdiagnostic overshadowingÕ, a process by which physical symptoms are misattributed to mental illness. This concept has received little attention in the psychiatric literature but mental health service users have reported its widespread occurrence (3) and its potential impact has been emphasized in two recent reports (4, 5). 'Diagnostic overshadowing' and learning disability The term Ôdiagnostic overshadowingÕ was first used in 1982 to refer to the tendency for clinicians to attribute symptoms or behaviours of a person with learning disability to their underlying cogni-tive deficits and hence to under-diagnose the presence of co-morbid psychopathology (6). Possible explanatory factors for the ÔovershadowingÕ include those related to the disorder (e.g. severity, specific psychiatric conditions), those related to the patient (e.g. degree of cognitive impairment) or those related to the clinician (e.g. years of experience, cognitive complexity) (7). The majority of studies investigating this phenomenon find ÔovershadowingÕ to exist, irrespective of such variables. One exception is the Ôcognitive com-plexityÕ of the clinician, which refers to the tendency of the clinician to view a presenting problem in a Ômulti-dimensional fashionÕ. Clini-cians who have greater Ôcognitive complexityÕ have been reported to be more likely to detect co-morbid psychopathology. There are limitations of such research. Most studies use clinical vignettes; so, the findings may be the result of a methodological artefact. However , despite possible limitations, such research is a starting point in trying to understand possible differences in clinical decision making for different patient groups. Worse physical health care in other minority groups Similar methods of research have been used to examine possible disparate care in other minority groups. However, whereas the focus in the learning disability research has been whether physical diagnoses are missed because of falsely attributing symptoms to the underlying learning disability, research of other minority groups has focussed more on possible bias or discrimination in diagnostic or treatment decisions because of race, gender or age. More sophisticated methods have been used in this research. In one study, investigators examined whether cliniciansÕ recommendations for cardiac catheterization differed according to the race and gender of the patient …