2. Classification and diagnosis
• Diagnosis – identification of the nature and cause of an illness
• Use of classification systems, in this case DSM-VI AND ICD-10
• All diagnostic tools require that the disorder:
• Must be significant in it’s disruption in everyday life
• Cannot be ascribed to any other disorder, symptoms or side effects of
medication
• Must be present long enough to be considered permanent behaviour
change
3. Classification and diagnosis – DSM-VI
• The diagnostic and statistical manual of mental health disorders, 4th edition
• Official classification system of the American psychiatric association
• Used worldwide
• Five axes on which disorders are assessed on; clinical disorders, personality
disorders and mental retardation, general medical conditions connected to
mental disorders, psychosocial and environmental problems such as limited
social support, global assessment of functioning (psychological, social and
job-related functions are evaluated on a continuum between mental health
and extreme mental disorder)
• Disorders then placed into categories; anxiety disorders, psychotic
disorders, mood disorders etc.
4. Classification and diagnosis –DSM-VI
• ‘There is no assumption that each category of mental disorder is a
completely discrete entity with absolutely no boundaries dividing it
from other mental disorders or from no mental disorder’
5. Classification and diagnosis – ICD-10
• The international classification of diseases, 10th revision
• Created by the world health organization
• Categorises diagnoses and is regularly updated to reflect changing
knowledge
• Recognises 11 types of mental disorder such as delusional disorders,
mood disorders, neurotic disorders, stress related disorders etc.
6. • Steinberger and Schuch (2002) found that in a sample of both
children and adults, 95% were diagnosed as OCD by DSM. From the
same sample, only 46% were diagnosed as having OCD by ICD criteria.
7. Reliability of diagnosis tools
• External reliability – the consistency of the tool in reaching the same
diagnosis for any given individual
• Internal reliability – the consistency of the tool in identifying the same
characteristics as specific for the disorder
8. How to improve reliability of diagnosis tools
• Inter-rater reliability – when several practitioners make identical,
independent diagnoses for the same individual
• HOWEVER
• Copeland (1971) gave a description of a patient to British psychologists and
American psychologists. 2% of British psychologists diagnosed patient as
schizophrenic, 60% of American psychologists diagnosed patient as
schizophrenic
• Test-retest reliability – when one practitioner makes the same consistent
diagnosis on separate occasions from the same information
9. Evaluation of reliability of diagnosis
• Reliable diagnoses are problematic because there are no physical
signs, only symptoms to base a decision on
• Wording of DSM-VI make it difficult to be objective – what is “average
people”?
• Cultural differences – DSM-VI imposing an American etic on other
countries, over inclusive. ICD-10 under inclusive
10. Validity of diagnosis
• A valid diagnosis has first got to be reliable though reliability is no
guarantee of validity
• Predictive validity – if treatment is successful, then the diagnosis is
considered valid
• Descriptive validity – patients diagnosed with different disorders should
differ from each other in order to have a valid diagnosis
• Aetiological validity – patients with the same disorder should have the
same cause
• HOWEVER
• Aetiological validity is hard to prove with schizophrenia as cause is largely
unknown
11. Validity of diagnosis
• Rosenham – On being sane in insane places
• Aim; to test the validity of schizophrenic diagnosis using DSM-VI
• Procedure; 8 volunteers admitted to different mental hospitals claiming to
hear voices but when admitted, acted normally
• A different hospital informed that unspecified number of pseudo-patients
would attempt entry over 3 months
• Findings; 8 volunteers took between 7 and 52 days to be released, 35 out
of 118 actual suspected pseudo-patients as sane
• Over the 3 months 193 patients were admitted, 83 who were thought to be
false patients – no actual pseudo-patients
• Conclusions; psychiatrists cannot distinguish between false and real
patients
• Evaluation; clinicians there to help, not turn people away which is why 8
volunteers originally admitted
• Doctors expected patients and so looked for them
12. Evaluation of validity
• However much the reliability improves, there’s no certainty that the
validity will improve
• Descriptive validity reduced by comorbidities (having two or more
disorders) which suggests that disorders are not actually separate
• Predictive validity difficult to obtain as treatments assigned from
biased viewpoints
• Winter (1999) ‘diagnostic systems are only aids to understanding not
descriptions of real disease entities’
13. Culture and gender bias in assessment and
treatment
1. British black people are more likely to be diagnosed as
schizophrenic, more likely to be institutionalized and more likely to
be given major tranquilizers and ECT.
2. Ethnic minority and working class are less likely to be referred for
psychotherapy than middle class people
3. Women are more likely to be diagnosed as psychiatrically ill
14. Why is there a culture and gender bias in
assessment and treatment?
• Clinicians are predominantly white, middle class males who are
ignorant of cultural and social situations of black, working class and
female patients
• CBSs – Cultural Bound Syndromes associated with particular cultures
such as Ghost sickness specific to Native Americans
• Perceived as ‘outside’ the classification systems of mainstream
western psychiatry
• Only western mental disorders are perceived as culturally neutral
