classification and diagnosis of SZ Flashcards
including Issues with
What are the issues surrounding the classification and diagnosis of schizophrenia
Reliability and validity
Define reliability (of a diagnosis)
The level of agreement and consistency of the diagnosis by different psychiatrists across time and cultures.
Define inter-rater reliability
The level of agreement and consistency of the diagnosis by different psychiatrists
Define test-retest reliability
The level of agreement and consistency of a diagnosis over time given no change in symptoms
Define Validity (of a diagnosis)
The extent to which SZ is a unique syndrom with characteristics, symptoms, and signs. To be valid, patients with SZ should have different symptoms from patients with other disorders
What are the issues affecting validity
- co-morbidity
- gender bias
- culture bias
- symptom overlap
- range of symptoms
define co-morbidity
When 2 or more conditions occur together in the same individual at the same time
define culture bias
A tendecy to interpret all phenomena through the ‘lens’ of one’s own culture, ignoring the effects that cultural differences might have on behaviour
Define symptom overlap
Shared symptoms that could lead to an incorrect diagnosis. Often calls into question teh validity of classification.
Define range of symptoms
The are a range of symptoms that could be present for a diagnosis of SZ. e.g. positive and negative symptoms.
Give evidence for co-mobitity affecting validity
Buckley et al 2009:
found that 50% of patients with SZ have depression or substance abuse, 29% had PTSD and 23% had OCD.
Give evidence for gender bias affecting validity
Longnecker et al 2010:
found that since the 1980s men have been diagnosed more than women
Cotten et al 2009:
suggests this underdiagnosis is due to women having more closer relationship so get more support which leads to women with SZ functioning better than men with SZ.
Give evidence for culture bias affecting validity
Keith et al 1991:
found that 2.1% of African Americans are diagnosed with SZ compared to 1% of the white population. Many people from african cultures believe and praised for being able to communicate with ancestral spirits. This means they are more likely to report these experiences which are often misinterpreted as symptoms of SZ.
Give evidence of symptom overlap affecting validity
There is considerable overlap between symptoms of SZ and other disorders. e.g. bipolar disorder. This means that it is hard to define the boundries between SZ and other disorders.
give evidence of range of symptoms affecting validity
2 individual could display very different behaviour but still be diagnosed with SZ.
for example the DSM-5 requires one positive symptoms whereas the ICD-10 requires 2 negative symptoms.
Give evidence for the reliablity of diagnosis of SZ
Osório et al 2019:
reports excellent reliability for SZ diagnosis (DSM-5) with an inter-rater agreement of +9.7 and a test-retest reliability of +9.2. This means that the diagnosis of SZ is consistently applied.
Give evidence against the reliability of diagnosis of SZ
Cheniaux et al 2009:
had 2 psychiatrists independantly diagnose 100 people using both the DSM and ICD criteria. Inter-rater reliability was poor, with one psychiatrist diagnosing 26 with SZ using DSM and 44 using ICD. The other diagnosed 13 with SZ using the DSM and 24 using the ICD. This poor reliability is a weakness of diagnosis of SZ.
What are the implications for a lack of reliability and validity when diagnosis SZ
A lack of reliability and validity in diagnosising SZ may result in misdiagnoses leading to providing incorrect or unnecessary treatment.
What are the advantages of classification and diagnosis of SZ
not in essay plan
- Communication (between mental health professionals)
- treatment (appropriate)
- prognosis (provides info)
- cause (can aid research)
What are the issues when classifiying and diagnosing SZ
- misdiagnosis
- labelling
- historical/ cultural context
Explain what is meant by misdiagnosis
individuals may be given the wrong treatment
explain what is meant by labelling as a issue of classifying and diagnosis SZ
Diagnosis leads to labelling. This can be helpful in providing the appropriate treatment, but can be stigmatised and lead to a self-fufilling prophesy
explain what is meant by historical/ cultural context as a issue of classifying and diagnosis SZ
Disorders in the diagnostic manuals may reflect social/political attitudes at the time e.g. homosexuality was included in the early manuals as a mental disorder. Not understanding an individual’s cultural frame of reference also leads to problems with diagnosis.
Breifly outline Rosenhan
Rosenhan had himself and 8 of his collegues who had no symptoms or history if mental disorders set up appointments at metal hospitals under fake names, occupations and employment. At the appointment they complained of hearing a voice saying “empty”, “hollow” and “thud”. Once they were admitted the psudopatients stopped simulating any psychiatric symptoms.
Evaluate Rosenhan
S – field study – higher in ecological validity than a lab
S - participant observation – got a lot of detailed data without the problem of demand characteristics
S – ethical - debrief to staff
W – ethical – staff being deceived
Give examples of positive symptoms of SZ
- hallucinations
- delusions
Give examples of negative symptoms of SZ
- avolition
- speech poverty
What is the prevelance rate of SZ in the general public
1%
When is the onset for SZ typically
early adult life - although this is later in women
describe how SZ is an episodic illness
there are periods of psychotic disturbances with periods of normal functioning
define hallucinations
an unusual sensory illness
Define delusions
irrational beliefs that can take many forms
Give some example of different delusions
- delusions of control - false belief that others can control their actions
- delusion of grandure - false belief that one possesses superior qualities such as genius or jesus.
- paranoia - false beliefs that a person or some individuals are plotting against them or members of their family
define speech poverty
a reduction in quality and amount of speech
define avolition
lack of interest and motivation or inability to engage in goal-directed behaviour
define positive symptom
Seen as an addition to a person’s normal behaviour
define negative symptom
Involve losses of behaviour seen as normal
