Evaluation Points Flashcards
Classification systems for Sz ?
DSM (diagnostic and statistical manual)- US
ICD (internal classification of disease) - Europe
Who produced the DSM 5 ?
American psychiatric association
Who produces the ICD?
WHO
What symptoms are required in the DSM 5 for diagnosis of SZ?
And how long must they be present ?
Delusions
Hallucinations
Disorganised speech and behaviour
Must be present for 6 months with 2 active symptoms
How many symptoms are required for the ICD?
1 symptoms
Positive symptoms of SZ ?
Delusions e.grandiose beliefs
Hallucinating (visual, tactile and auditory)
Disorganised speech
Catatonic behaviour
Negative symptoms?
Loss of severe reduction of normal functioning
- speech poverty (limited speech output)
- avolition (no goal directed behaviour)
- affective flattening (reduction in range and intensity of emotional expression)
Prevalence of Sz?
1% risk in general population
Most of Sz?
For most is a gradual descent over 6 months with odd idea and psychotic episodes
Risk factors that trigger genetic vulnerability ?
- low socio economic status
- urban residence
- minority ethnicity
Why do we use classification systems ?
Makes it easier to identify and breakdown and treat disorders
- increases reliability of diagnosis (doctors more likely to arrive at same diagnosis when using classification systems
What is reliability in diagnosis ?
= consistency
- for diagnosis to be replicable it must be repeatable
Aka test retest reliability
How can we test diagnosis in Sz?
Inter inter-rate agreement
- 2 clinicians must reach same conclusion about a patient
- agreement should be same over time and cultures
How is the inter eater reliability between the DSM and ICD?
Poor
- Cheniaux,2 psychiatrists independently diagnose 100 patients using ICD and DSM
Findings
- both diagnosed twice as many with SZ when using ICD over DSM
- one psychiatrist diagnosed twice as many as the other
Why is the inter-rated reliability between ICD and DSM so poor ?
- some clinical characteristic are open to interpretation such as eccentric and delusional
- symptom threshold for diagnosis is higher in DSM, 2 vs 1
- cultural differences, in US and UK more African Americans are diagnosed with SZ due to lack of cultural awareness e.g hearing voices is more acceptable in African cultures as you believe u can communicate with ancestors = less bizar behaviour, this leads to clinicians having to take extra care in assembler for people from different ethnic groups
What is validity in diagnosis of SZ ?
Extent to which Sz is a unique syndrome with a shared set of characteristic, distinct from other disorders = extent to which different classification systems measure what they claim
to measure
Why are validity and diagnosis linked ?
Because a diagnosis isn’t valid if it’s not reliable
Why is diagnosis in validity of Sz problematic ?
Symptoms and development of disorder varies enormously so it’s not really a unique condition syndrome with shared set of characteristics
Difficult to define boundaries between Sz and other disorders
3 areas In validity for Sz ?
Gender bias
Symptom overlap
Co-morbidity
Gender bias ? In diagnosis, studies
- extent to which diagnosis is dependent on gender of a person
(Longnecker et al found since 1980’s) mehave been diagnosed more than women
Is this gender bias or genetic vulnerability
- Loring and Powell
Randomly selected 290 female psychiatrists
- 2 case studies were read
- 56% diagnosed when patient was male
- 20% diagnosed when patient said to be female
- gender bias is less evident in female psychiatrists suggesting gender bias is also effected by gender of clinician
Reason for gender bias in diagnosis?
- female patients usually function better than men and more likely to have better relationships with family which may cause under diagnosis as Symptoms may be masked as higher functioning
What is symptoms over lap in areas in validity?
- many pos and beg symptoms found in Sz and no polar disorder e.g delusions and hallucinations seen in both
- class into questions validity and diagnosis of Sz = extent to which Sz is a unique disorder
Co-morbidity In validity of Sz?
And studies ?
Extent to which two or more conditions occur together
- if two or more conditions occur together a lot it calls into question validity of diagnosis and classification of Sz as may just be a single condition
- Buckley concluded patients with Sz have following comorbid conditions
- 50% have depression
- 47% substance abuse
- 23% OCD
In terms of diagnosis- If half are diagnosed with depression maybe were bad at telling difference between the 2
In terms of classification- maybe severe depression looks a lot like Sz and visa Versa, maybe they should be a single conditions
Ethical issues with labelling ?
- label in of Sz strays on medical record forever
- can hamper recover as becomes self fulfilling prophesy
- people suspicious of such labels
