Discuss issues surrounding the classification and diagnosis of schizophrenia

Validity is regarded whether a diagnostic system assesses what it claims to be assessing. However, the boundaries between schizophrenia and other disorders can often be difficult to define, such as, mood disorders and development disorders such as autism. Very different problems can be presented by different patients diagnosed with schizophrenia. According to ICD and DSM, only two potentially quite different, symptoms need to be present in order to diagnose schizophrenia. This suggests that there is no single underlying causal factor - a further reason to question the validity of schizophrenia as a disagnosis.

The term predictive validity refers to the ability of the classification system to predict the course of the disorder and the response to treatment. However, it is proved to be very difficult to predict accurately the ICD and DSM validity and there are wide individual variations. About one-third of patients have one episode or a few brief episodes of schizophrenia then fully recovering. Another one-third, throughout their lives have occasional episodes and function reasonably effectively between episodes. The remaining patients deteriorate over a series of increasingly incapacitating episodes. Between 10-15% of people with schizophrenia commit suicide.

Co-morbidity is described as a patient who suffers from two or more mental disorders at the same time. Sim et al. (2006) studied 142 hospitalised schizophrenic patients in which 32% of that had an additional mental disorder. Co-morbidity occurs in part because the symptoms of different mental disorders often overlap with each other. An example of this might be, schizophrenia and major depressive disorder both involve very low levels of motivation. This creates a problem of reliability, whether the low motivation reflects the existence of depression or schizophrenia, or both. There is a growing trend to diagnose patients as suffering from 'co-morbidity disorder". This may be because many individuals do not neatly fit into a category that has been created. Instead of acknowledging that the methods by which diagnostic decisions are arrived at are lacking validity, clinicians diagnose two separate disorders.

One way cultural biases can affect the diagnosis of schizophrenia is by causing clinicians to over/underestimate psychological problems in members of other cultures. Although across all cultures, schizophrenia can occur, there is a more consistent finding in the USA and the UK that schizophrenia is diagnosed more frequently to those who are African-American and African-Caribbean than in other groups. 2.1% of African-American are diagnosed with schizophrenia, compared with 1.4% of white Americans (Keith et al. 1991).

There are three possible reasons for the difference in the rates of diagnosis - genetic vulnerability, psychosocial factors associated with being part of a minority group (e.g. racism) or misdiagnosis. It could be the case that clinicians from the majority population misinterpret cultural differences in behaviour and expression as symptoms of schizophrenia.

Davison et al. (2004) found that clinicians were more likely to diagnose a patient as having schizophrenia if the case summer referred to the person as African-American than if she/he was described as white.

However, the DSM-IV-TR attempts to improve cultural sensitivity by providing a general framework for evaluating the role of culture and ethnicity, compared to the early editions of DSM which were criticised for the lack of attention to cultural and ethnic variations in psychopathology.

Patients being diagnosed with schizophrenia can have many negative effects on them. A person diagnosed with schizophrenia might become fearful of another episode, or unable to deal with new challenges as they have lost confidence to use this ability.

Critics argue that placing a person in a diagnostic category distracts from understand the person as a unique human being, but that instead the label can be used to describe the person instead of the disorder. This can lead to prejudice towards the individual with schizophrenia - e.g. dangerous, unpredictable or unemployable.

Once labelled with schizophrenia, it is extremely difficult to remove - whether they suffered one episode of schizophrenia or lots and recovered, they may still always be labelled 'schizophrenic'.

Although there are serious issues to do with classification, there are arguments for why classification is used in psychopathology - to make communication between professionals easier; to predict the outcome of the disorder and to choose appropriate treatment and to understand more about the possible causes of mental disorder, are only a few to name.

A2 Psychology Sam Wong