Schizophrenia - Diagnosis and Classification (Culture Bias - more common…
Schizophrenia - Diagnosis and Classification
(International Classification of Disease) -
Two or more negative symptoms
(loss of normal abilities) across 1 month is sufficient for diagnosis.
- Difficult to keep up with
poor hygiene, lack of persistence in work, lack of energy
- changes in patterns of speech.
Reduction in amount/quality
Delay in verbal responses
(Diagnostic and Statistical Manual) -
One positive symptom
(additional experiences beyond ordinary existence) must be present across 6 months
Unusual sensory experiences
, either resembling current environment or not.
E.g. voices talking to/about the patient
(often criticising). Relate to all senses.
. Also known as
. E.g. being an
important historical, political or religious figure
(e.g. by government), having
, believing body is under
Reliability: Elie Cheniaux
- two psychologists independently diagnose
using ICD and DSM. One psych diagnosed
44 with ICD and 26 with DSM
, and the other diagnosed
24 with ICD and 13 with DSM
. Poor inter-rater reliability.
- two or more conditions occurring at the same time.
because could be one single condition.
Difficult to know how to diagnose schizophrenia.
found co-morbidity rates with schizophrenia patients:
47% substance abuse
: Longenecker - since 1980s men have been diagnosed more with schizophrenia.
Likely explanation -
women patients typically function better with symptoms
(symptoms perhaps seen as not extreme enough)
: 290 psychiatrists asked to diagnose same two patients.
If told it was a male, 56% diagnosed schizophrenia. If told female, 20% diagnosed schizophrenia
. Psychiatrists mostly men, when they were female, bias disappeared.
Cheniaux: Criterion Validity
- study with two psychiatrists showed people much
more likely to be diagnosed with ICD than with DSM
. Either over-diagnosed with ICD or under-diagnosed with DSM.
7 friends and students
faked one symptom
All were admitted
, where they began behaving normally again. Asked if they could leave, said they felt fine when asked. They were kept in.
Diagnosis clearly not valid as they were diagnosed when they weren't actually schizophrenic
, and could not recognise that they were behaving normally.
- overlap between symptoms of schizophrenia and other conditions.
schizophrenia and bipolar
positive symptoms like delusions
negatives like avolition
. Also similarities with
dissociative identity disorder
of diagnosis and classification. ICD may diagnose schizophrenia but DSM may diagnose another condition
- more common in African-Americans and English people of Afro-Caribbean origin.
Not down to genetic vulnerability because rates in Africa and West Indies are not high.
Positive symptoms like hallucinations perhaps more acceptable in African cultures (cultural beliefs of communication with ancestors). These could be seen as bizarre or irrational when reported to a psychiatrist in another culture.
White psychiatrists may distrust black people during diagnosis.
Copeland: British/American psychiatrists given a patient to look at. 69% Americans diagnosed schizophrenia, only 2% of British diagnosed. Both used DSM. Low reliability.