Diagnosis is based on the self-reported experiences of the person as well as abnormalities in behaviour reported by family members, friends or co-workers, followed by secondary signs observed by a psychiatrist, social worker, clinical psychologist or other clinician in a clinical assessment. There is a list of criteria that must be met for someone to be diagnosed, these depend on both the presence and duration of certain signs and symptoms, an initial assessment includes a comprehensive history and physical examination by a physician. Although there are no biological tests which confirm schizophrenia, tests are carried out to exclude medical illnesses which may rarely present with psychotic schizophrenia-like symptoms.
The most widely used criteria for diagnosing schizophrenia are the DSM-IV-TR, and the ICD-10. The DSM-IV criteria asks for symptoms to have been present for at least six months, deterioration of functioning and two of the symptoms noted must be shown. The current methods of diagnosing and then classifying mental disorders is difficult because the process largely depends on clinical impressions rather than pathology reports. The main data the psychiatrist has is the appearance and behaviour of the patient and the way he/she describes their thoughts.
Looking through a list of varying case studies and the clinical symptoms shown I wouldn’t categorise all of them as schizophrenic, but to my surprise they were all past studies of patients later diagnosed as schizophrenic. Through this activity a big limitation was revealed; diagnoses rely on the psychiatrist’s opinion which obviously varies from each psychiatrist, leading to low reliability. Supporting evidence can be found in Rosenhan’s famous study ‘Sane in insane places’. In which ‘sane’ people presented themselves to psychiatric hospitals in the US claiming they heard unfamiliar voices in their heads saying the words ‘empty’ ‘hollow’. They were all diagnosed as having schizophrenia and admitted. Throughout their stay, none of the staff recognised that they were actually normal. In a follow up study, Rosenhan warned hospitals of his intention to send out more pseudo patients. This resulted in an apparent 21% detection rate, although no pseudo patients actually presented themselves, so it wasn’t them being chosen. It is clear that we cannot distinguish the sane from the insane in psychiatric hospitals” and also illustrated the dangers of depersonalization and labelling in psychiatric institutions. It suggested that the use of community mental health facilities which concentrated on specific problems and behaviours rather than psychiatric labels might be a solution and recommended education to make psychiatric workers more aware of the social psychology of their facilities. This study showed odd behaviour was labelled as schizophrenic and these individuals would be admitted if their symptoms were known. This supports the labelling theory, as people labelled as schizophrenics would believe this professional opinion and may show symptoms of schizophrenia, retrospectively the diagnosis would then be regarded as correct. The wardens perceived the pseudo patients normal behaviour as psychotic due to the label. This shows diagnoses aren’t reliable; they were labelled due to behaviour which deviates from what society regards as ‘normal’. It agrees odd behaviour leads to being labelled ‘odd’ which then leads to labels of being ‘schizophrenic’ but it doesn’t necessarily agree that the label causes schizophrenia.
Psychotic symptoms that would be thought to be characteristics of schizophrenia can also be experienced by non schizophrenic people like regularly “hearing their name called out” as they’re going to sleep. These are called hypnagogic hallucinations, by definition these people do hallucinate, they hear their name called when it’s not called, but in the absence of additional symptoms they are not suffering from schizophrenia. This detracts from the reliability of the DSM criteria, other symptoms such as disorganized speech could also be eccentric behaviour, or a mood disorder not necessarily psychotic. There is a big blurring of boundaries between schizophrenia and other disorders. For example a case study of a 19 year old called Maria who had displayed symptoms such as “flat emotions…her lecturer was a demon” – there was a lack of psychotic symptoms, but rather symptoms which would come under the classification of a mood disorder, which questions the validity of diadnoses made. The reliability of diagnosis in szhiophrenia is further challenged by the finding that there is massive variation between countries. Copeland et al (1971) gave a description of a patient to 134 US psychiatrists and 194 british psychiatrists. 69% of the US psychiatrists diagnosed schizophrenia but only a shocking 2% of the british ps gave the same diagnosis. Reliability is the extent to which ps can agree on the same diagnoses when independently assessing patients which in this study shows a massive difference; therefore showing incredibly low reliability and therefore not applicable. The definitions used for criteria lack consistency, this is particularly relevant to the evaluation of ‘bizarre and non bizarre delusions’. 50 senior ps were asked to differentiate between the two, they produced inter-rater reliability correlations of only around 4.0, forcing the researchers to conclude that even this central diagnostic requirement lacks sufficient reliability to be a reliable method.
Thomas Szasz claims that the categorised mental disorders are passed off as having been scientifically determined, they’re actually judgements that act as excuses for the use of power by psychiatric authorities. He believes it’s a label that simply serves to provide justification for psychiatric theories and treatments, a vastly elaborate social control which disguises itself under the claims of scientific evidence. Obviously the big limitation of his theory is that there is significant correlations between genetics and the likelihood of developing schizophrenia.
There are many varying views about the reliability and validity of the classification and diagnosis of schizophrenia, but it has proved to be the best method we have. Reliability has improved, and it’s better if we use standardised testing tools.