Issues of Bias in Diagnosis

Diagnosis On your sheet explain how a psychologist would be confident in saying an individual has a particular mental illness. Mention the importance of a classification system

Bias A bias means that certain people or groups of people are more likely to be classed as having a particular disorder than other types of people.

The BIG question The issue is the cause of the bias: Does the bias come from the system being used to make the diagnosis (so that some groups tend to be misdiagnosed as having an illness when they don’t)? Or is there is an actual difference in the rates of mental illness between different groups of people (in which case, the diagnostic system is accurate)?

Cultural Bias in Diagnosis In Britain, certain cultural groups are more frequently diagnosed with some disorders. Eg people of African descent are more likely to be diagnosed with schizophrenia. Give TWO opposing explanations for this fact

Explaining Cultural Differences While this evidence suggests that a bias in diagnosis exists, it does not give us any information about the nature of this bias. Is there a bias in the diagnosing, OR is there a genuine difference in the rates of schizophrenia between those of African descent, and others?

Explaining Cultural Differences Over-diagnosis due to inadequate diagnostic methods Bias in the diagnostic tools (DSM IV and ICD) which are Western Bias in the Psychological Tests Bias in the psychologist

Explaining Cultural Differences Genuine differences in rates of mental illness. Stress of being a minority? - Littlewood (1980) Unlikely - bias applies only to black people Littlewood & Lipsedge (1989) Also, higher rates among 2 nd generation immigrants

Explaining Cultural Differences Genetic Differences? African vulnerability to schizophrenia? WHO – check findings p231 Littlewood(1989) Opposes – why?

Explaining Cultural Differences Type 1 or Type 2 error? Type 1 Put healthy individuals in institutions Type 2 Leave sick people out in the community Which is worse / more dangerous?

Explaining Cultural Differences Type 1 or Type 2 error? Malgady (1996) Denying cultural bias could lead to type 2 errors (not treating sick people) Trying to avoid Type 2 errors leads to Type 1 errors (locking up healthy people) Malgady thinks this is preferable (Complicated - but try to grasp this)

Explaining Cultural Differences What does Vitamin D have to do with cultural differences? Read the article – how does it explain the aetiology of schizophrenia? Where does culture come in?

Gender Bias in Diagnosis