There are many problems with reliability, such as an individual will not give the same information to different clinicians, also there may be insufficient time to collect valid information. A study which shows that diagnoses can have good reliability but bad validity is Rosenhans study. Rosenhans conducted an experiment in which he sent 8 psedopatients to psychiatric hospitals. They claimed they were hearing voices saying empty, hollow and thud. Once admitted the pseudo patients were asked to act normally, report that they felt fine and no longer heard voices. In the second part of the experiment involved asking staff at a psychiatric hospital to detect non-existent fake patients, the staff falsely identified large numbers of genuine patients as impostors. This study shows that psychiatrist labels tend to stick in a way that medical labels do not. Everything a patient does is interpreted according with diagnostic label. The study also shows the DSM cannot always diagnose the people correctly.
Another issue we are going to look at that causes bias in the diagnostic system is culture. Culture is an important issue when placing a diagnosis on someone. Culture is a set of beliefs and practices that characterizes a group of people; culture varies over the world with different ethnic groups such as Jews, Muslims Christians and Hindus etc. However due to different cultures, bias can occur in the diagnostics system. These biases are such as cultural attitudes- attitude can affect the reporting of symptoms which will affect prevalence and incidence rates. Studies which show different cultural attitudes that affect diagnoses are shown below:
Kim and Berrios (2001) found that in some Asian languages schizophrenia directly translates to dieses of the disorganized mind, they also found in Japan that this idea is so stigmatizing that only 20% of patients are aware of their disorder. Another study conducted by Cinnerella and Lowenthal (1999) - conducted an in-depth interview with 52 participants in Britain. Participants consisted of white catholic, Hindus, black Christian, Muslim and Jews. They found that all groups saw depression as a result of life events. 4/5 had a fear of being misunderstood by the health professional. Black Christians and Muslims believed depression and schizophrenia had a social stigma and believed that prayer would solve the problem. This study shows that different cultures have different attitudes toward there problems for example black Muslims and Christians, this will affect the persons decision to seek help or not. Therefore cultural attitudes can cause bias in the diagnostic system.
Other issues which effect culture bias are vulnerability; different cultures are more likely to react differently to health problems. A study conducted by Levav et al (1997) compared incidence rates of alcoholism and depression in American Jews and Catholics and Protestants. They found that Jews had the highest incidence rates for depression and lowest incidence rates for alcoholism.
Culture bound syndrome also plays an important role in bias in the diagnostic system. This is the belief that disorders are specific to a certain culture. Berry et al (1992) highlighted 3 types of syndromes these were absolute- the same symptoms and incidence rates. Universal- same symptoms but incidence rates vary throughout world, and culturally relative- symptoms unique to that culture. An example of culture bound syndrome is koro- the belief that sexual organs are shrinking and disappearing into the abdomen. In conclusion all these culture issues can cause a problem when diagnosing someone with the DSM.
As you can see with the issues above there is clearly bias in the diagnostic system these can be due to cultural, social and interpretation issues.