issues with classification of SZ Flashcards
what is classification?
- organisation of symptoms into categories based on symptoms that appear together in most sufferers
why is classification difficult when diagnoising SZ?
- hard to make reliable diagnosis because SZ can be easily confused with depression if patient doesnt report illness accurately.
- diagnosed during clinical interview-> self report + subjective
how do you diangose SZ with the DSM?
need 2 symptoms
- delusions
- hallucinations
- disorganised speech
1 of these MUST be present
- negative symptoms
needs to be active for 1 month, have significant impairement for 6 motnhs and syptoms cannot be due to substance/medication
- America
how do you diagnose with the ICD?
need either
1 of these positive symptoms:
1. hallucinations
2. delusions
3. thought disorder
OR 2 of these negative symptoms:
1. apathy
2. paucity of speech
3. blunt effect
- for 1 month
- recognises diff subtypes of SZ
- worldwide
how is the reliability of the diagnosis tested?
- using inter-rater reliability
the extent to which 2 different mental health professionals amue at the same diagnosis
research for reliability of diagnosising with ICD and DSM?
Cheniaux et al
- 2 psychatrists indepently diagnose 100 patients using ICD and DSM
- reliability of diagnosis is low as the results were different using the same method
- low inter-rater reliability
what is criterion validity?
a way of assessing validity by comparing the results with another measure
what does SZ diagnosises suggest about criterion validity?
low-> amount of diagnosis vary between the methods, more likely get diagnosed with ICD
research for the validity of diagnosing SZ?
Rosenhan
- 8 confed acted as fake patients going to mental hospitals claiming to hear voices, all admitted. once on ward they stopped pretending to have symptoms, only discharged when convinced staff they were sane.
does diagnosing have high or low validity?
low-> rosenhan showed that psychatrists cannot reliabily tell the difference between an insane and sane person
counters for Rosenhan research?
- outdated 1973
- self-report method
- unethical
- lacks temporal validity
what is co-morbidity?
when two or more conditions occur together
research for co-morbidity?
Buckley et al
- almost half SZ patients also diagnosed with depression (50%), substance abuse, PTSD, or OCD
- SZ co-morbid with other disorders\
- questions validity of classification of both illnesses-> cant tell diff between two?
why is co-morbidity a problem?
- creates overlapping classification
- misdiagnoses and leads to innaccurate diagnosis
examples of SZ having symptoms overlap?
- bipolar-> shared pos symptoms (delusions) and negative symptoms (avolition)
- depression-> shared neg symptoms like avolition + flat affect
why is symptom overlap an issue?
- misdiagnosing/ unsure which condition to diagnose with=lacks validity
- is SZ a condition on its own? is it a subtype of bipolar depression?
what is gender bias?
when accuracy of diagnosis is dependent on the gender of the individual
gender bias in diagnosing?
- men more common (1.4:1 ratio), could be due to genetics
- research= women function better than men socially, cope better. leads to under-diagnosis in women as masks symptoms.
does gender bias have high or low validity?
LOW-> bias diagnosis
Loring and Powell
gender bias-> patient described as male 56% gave diagnosis of SZ, when female 20% gave diagnosis. enforcing sterotypes
what is culture bias?
differences in diagnosis across cultures
statistics across cultures for SZ?
- Afro-Carribbean origin upto 10 times more likely than white diagnosed
how is there a culture bias in diagnosising?
- doctors dont judge culture norms accurately and misinterpret symtoms due to cultural diffs
- eg hearing voices more acceptable in African cultures so they r more likely report this, western culture= irrational, mislabel symptom
how does culture bias reduce the validity?
- underdiagnoses white people
- if doctor doesnt understand patients culture they may misinterpret experience and give wrong diagnosis
- must take cultural differences and norms into consideration
