Classification and diagnosis of psychological abnormality

ICD - The International Standard Classification of Diseases, Injuries and Causes of Death

The main functions of the ICD is to facilitate the collection of general health statistics. Mental disorders were first included on the list in 1952 and form only one small section of the manual. The ICD has been revised a number of times and is currently in its 10th edition. The APA and WHO are working together to bring the relevant sections of the DSM and ICD into line with one another so there is a greater consistency. It identifies 11 general categories of mental disorder. 

WHO = World Health Organisation APA = American Psychiatric Association

 For nearly half of the disorders identified, symptoms must be sufficient to cause 'clinically significant distress or impairment in social, occupational, or other important areas of functioning'. In contrast, ICD-10 do not include the social consequences of the disorder. 

One important difference between DSM and ICD is that the DSM-IV-TR organises each psychiatric diagnosis into five levels (axes) relating to different aspects of disorder or disability.

• Axis I: clinical disorders, inc. major mental disorders, as well as developmental and learning disorders (depression, anxiety disorders, schizophrenia
• Axis II: underlying pervasive or personality conditions, as well as mental retardation (antisocial personality disorder, problems or intellectual development)
• Axis III: Acute medical conditions and physical disorders (inc. medical problems that could lead to or exacerbate mental disorders e.g. brain injuries)
• Axis IV: psychosocial and environmental factors contributing to the disorder
• Axis V: Global Assessment of Functioning or Children's Global Assessment Scale for children U18 (on a scale on 1-100). This scale is used to rate the ability to function socially, psychologically and at work. A score of >90 indicates superior functioning, while <30 indicates serious impairment. 

The clinician is required to make a thorough examination of the individual and to consider his/her symptoms and behaviour in the light of all five axes. This is an attempt to improve the accuracy and reliability of diagnosis. 

Early versions of the manuals were not very reliable. Reliability in this context means the likelihood of different clinicians using the same system to arrive at the same diagnosis or a particular patient. There were several reasons for the low reliability. 

- Key terms were not clearly defined

- Clinicians used different techniques when interviewing and assessing patients

These two problems have since been addressed and more detailed, operational definitions have been included in  later versions of the manual. Most psychiatrists now also use standardised interview schedules when assessing patients and taking their clinical history e.g. to Present State Examination (PSE) (Wing et al 1974). Wing and colleagues have also developed computer programs such as CATEGO which generate a diagnosis based on a rating of the symptoms. This eliminates any personal bias on the part of the clinician. 

- The diagnosis of sz has been very widely used in the past, and prior to the 1970s there was a significant difference in the prevalence rates of sz in different countries. In America particularly, the diagnosis was used liberally in comparison to other countries because their classification systems used broader definitions. In the US, 20% of patients were diagnosed with sz in the 1930s, but this rose to 80% in the 1950s. At the Maudsley Hospital in London, the diagnosis rate of 20% remained the same throughout this period (using ICD, Cooper, 1972). In order to eliminate these diagnostic differences, attempts were made to bring the various classification systems more  into line with one another, and ICD and DSM are now very similar. 

- However, there are several other diagnostic tools in addition is ICD and DSM that have been developed specifically to help clinicians diagnose sz (e.g. Schneider Criteria, Research Diagnostic Criteria etc) and which are still used by clinicians. The use of such criteria can actually improve the reliability of diagnosis. For example, Farmer (1988) found high levels of reliability using the standard interviewing technique known as PSE (Present State Examination). Reliability in this sense means the different clinicians using the same criteria arrive at the same diagnosis. However, the fact that the different criteria have been used to disgnose sz make it difficult to research. In studies of treatment outsomes, for example, it is difficult to compare data based on individuals who have been disgnosed with sz using different criteria. 

- Szasz (1979) has questioned the whole concept of mental illness and has suggested that the process of diagnosis is just a form of politically sanctioned social control. 

- Scheff (1966) believed that people labelled with a diagnosis will conform to the label and it therefore becoms a self-fulfilling prophecy. While this is clearly an inadequate explanation for a serious disorder like sz, it is nonetheless true that mental illness labels stick, and they can be used to describe the person rather thanthe disorder. 

Criticism: The 'Myth of Mental Illess'. IDA - BIOLOGICAL V SOCIAL APPROACH

Some people have challenged the whole idea of treating mental disorder in the same way a physical disorder. Thomas Szasz (1962) dismissed this approach as the 'Myth of Mental Illness'. He believed that it encourages us to interpret problems of living as if they are illnesses. As a consequence, we remove all responsibility from individuals for solving their own problems and we run the risk of administering inappropriate, even damaging, treatments. If the concept of mental disorder is itself controversial, any classification of mental disorders are likely to be controversial as well. He believed that doctors were in a league with drug companies; one to diagnose us ill, the other to sell the drugs. He is quoted as saying "the last bastion of the consumer is death"

Response

Szasz's view is not accepted by many psychologists. There is considerable evidence for the existence of certain distinct syndromes e.g. sz, and little support for the idea that such a devastating condition can be brought about simply by stressful living. 

Criticism - Stigmatising

• Some critics say that placing a patient in a disgnostic category distracts from understanding that person as a unique human being with an individual set of difficulties. This can lead to stigma whereby an individual with a 'mental illness' is wrongly judged, e.g. as dangerous, unpredictable, incurable, unemployable etc. 
• Some sociologists have suggested that labelling socially deviant behaviour as illness simply increases the individuals difficulties e.g. by attracting stigma

Response

• It is not the diagnostic label that leads to stigma. People with mental disorders were stigmatised long before modern diagnostic categories were used. Stigma will only be reduced when there is 'better public understanding of the true nature of some mental illnesses', This process is helped by the recent trends for prominent people to talk publicly about their own mental illnesses e.g. Stephen Fry. 
• Clinicians working within psychopathology argue that mental illness should only be diagnosed in the presence of a range of symptoms, not solely in terms one socially deviant behaviour. 

Criticism - Failure to categorise some individuals

Individuals do not all fit neatly into the diagnostic categories. Some meet the criteria for more than one and others do not fit into an existing category at all. 

Response

It is true that a few individuals do not fit into the existing categories, but this is not a good reason to abandon classification systems for the majority who do. 

Criticism - Abuse in psychiatric disgnosis

There have also been cases of abuse in psychiatry where diagnoses have been made for political reasons. In the Soviet Union there were instances where psychiatrists colluded with the government to classify political dissidents as mentally ill. 

Response 

Fortunately, cases like this are rare, but it is very important that clinicians use psychiatric diagnoses carefully and appropriately. 

Eight psychiatrically 'normal' people presented themselves at the admissions office of 12 different psychiatric hospitals in the USA, complaining of hearing voices saying 'empty', 'hollow' and 'thud' (auditory hallucinations). These symptoms, together with their name and occupation, were the only falsification of the truth that was involved at any stage of the study. 

All eight pseudo-patients were admitted (in 11 cases with a diagnosis of 'schizophrenia', in the other, 'manic depression') and once this had occured they stopped claiming to hear voices; they were eventually discharged with a diagnosis of 'schizophrenia (or manic depression) in remission' (i.e. without signs of illness). The only people to have been suspicious of their true identity were some of their 'fellow' patients. It took between 7-52 days (average 19) for them to convince the staff they were well enough to be discharged. 

In a second experiment, members of a teaching hospital were told about the finding of the original study and were warned that some pseudo-patients would be trying to gain admission during a particular three-month period. Each member of staff was asked to rate every new patient as an impostor or not. During the experimental period, 193 patients were admitted, of whom 41 were confiently alleged to be impostors by at least one member of staff, 23 were suspected by one psychiatrist and a further 19 were suspected by one psychiatrist and one member of staff. All were genuine patients. 

The study tells us nothing about the accuracy of diagnosis, rather the study was assessing whether people pretending to have mental disorders could be detected. Spitzer (1975) observed: 

• On the basis of the clinician's data, no diagnoses other than those given were justified. Each participant insisted on admission, which itself an important symptom of emotional disturbance. A person who swallowed a pint of blood and then went to hospital vomiting blood would probably be diagnosed as having a peptic ulcer. Just because the physician failed to notice the deception would not imply that diagnosis was impossible.
• The pseudo patients behaviour was not normal after admission: normal people would say 'im not crazy, i just pretended to be. Now I want to be released'. At least initially, the pseudo patients remained impassive. 
• The label 'in remission' is very rarely used and implies that the psychiatrists knew that there was something different about the pseudo patients. All the non-psychotic people observed by the psychiatrists were, by virtue of being given the label 'in remission', diagnosed as non-psychotic. 
• The use of the word 'insane', while catchy, is inaccurate. Insane is not a psychiatric diagnostic category, but a legal term decided in a court of law. As such, Rosenhan used the term incorrectly.