Diagnostic classification systems: There is no one manual for diagnosing mental illness. There are two classification systems which are most widely-used in western cultures:
- The APA’s (American Psychiatric Association) Diagnostic and Statistical Manual of Mental Disorder (known as the DSM) which is the most commonly-used manual, and is now in its fourth edition, the latest being the text-revised version, called DSM IV-TR
- The WHO’s (World Health Organisation) International Statistical Classification of Diseases and Related Health Problems (known as the ICD), which is similar to the DSM although not quite as widely-used, but it shares the same sort of strengths and weakness – the ICD is now in its tenth edition, ICD-10
The DSM provides criteria from which mental health disorders can be diagnosed. The content of the DSM has changed significantly since the publication of DSM-I in 1952, and there are to be many more updates and amendments in the upcoming fifth version, DSM-5 (previously DSM-V) which is due to be published May 2013.
With each new version of the DSM, definitions have become more precise (for example, by including the duration of symptoms needed for a diagnosis), and also changed have been made in line with changing social norms (for example, homosexuality in DSM-I and DSM-II was considered a mental illness). New disorders are also outlined in each edition.
The multi-axial system: The DSM is used as a diagnostic manual, and the DSM’s system of diagnosis uses a five-axes model. Each axis measures a different aspect in relation to the disorder. Axes 1-3 are compulsory, whereas axes 4 and 5 are optional, although are usually included as well for a more reliable diagnosis. Having multiple axes allows a patient to be assessed by more than one criterion, so a patient is put into a category on each axis using their symptoms and a diagnosis can be made from this.
- Axis I measures the clinical disorder, this gives the major diagnostic category arrived at by the diagnostician, so disorders such as schizophrenia, depression, bulimia , sleep disorders, etc. would be described under this axis (axis I will also include anything which requires immediate intervention, such as history of sexual abuse or stress-related physical symptoms which need quick attention)
- Axis II measures personality disorders and mental retardation (based on a ratings scale), and these chronic conditions often go alongside the axis I disorders, and help understand these disorders – these are clinical syndromes that are a permanent part of the patient and may affect treatment, such as OCR or paranoid personality disorder
- Axis III assesses general medical conditions, these are physical problems that are of relevance to the condition or treatment – for example, if the patient has diabetes, this could contraindicate the use of certain drugs – and these conditions may contribute to the patient’s ability to cope and their self-image
- Axis IV measures psychosocial and environmental problems (life problems that influence the psychological wellbeing of the patient) – examples include homelessness, family issues and unemployment
- Axis V gives a score for the global assessment of functioning, whereby a score from 1 to 100 is used to classify the patient based on an evaluation of how well the individual functions socially, occupationally and psychologically where a score of 1 means ‘severe danger of harm to self or others’ and 100 shows the individual has superior functioning in a wide range of activities (generally, a score of 50 or below indicates severe symptoms)
Changes in the DSM: There have been a number of revisions to the DSM, partly in response to criticisms such as that arising from Rosenhan’s study of what it was like to be sane in insane places. Rosenhan found that eight ‘normal’ people were accepted as mentally ill by mental health institution, highlighting the lack of validity in diagnosis of mental illness at the time. As a result, the DSM was revised to take such criticisms into account.
During revision, the DSM is studied by many groups of people, who consult research as well as other data about diagnoses. Sometimes there is lobbying to get aspects changed
Strengths and weaknesses of the DSM:
| Strengths | Weaknesses |
| • The main strength of the DSM is that it is in such wide use and is commonly agreed upon. This allows for a common and universal diagnosis. Through its many revisions, the DSM has stood the test of time. Having a diagnostic companion such as the DSM or ICD allows, theoretically, for two doctors to make the same diagnosis on the same patient – if the symptoms are the same, a more agreeable diagnosis is likely using the DSM. | • However, some criticise the DSM because it serves as confirmation that sufferers of these conditions are ‘sufferers’ who need ‘treatment’, although some suggest mental illness is often just another way of living, who’s to say they’re actually suffering a mental disorder? Laing (1960) suggested that schizophrenia is just another way of living and not a condition |