Schizophrenia Flashcards
(23 cards)
What is schizophrenia
A long term mental disorder involving a breakdown in the relation between thoughts and behaviour leading to faulty perception and withdrawal from reality
Type I schizophrenia:
Characterised by delusions, hallucinations and unwanted intrusive thoughts
Thought to be the result of abnormal levels of chemicals in the brain
Type II schizophrenia
Negative symptoms:
Avolition (lack of motivation)
Anhedonia (lack of pleasure)
Catonia (immobility)
Disorganised speech
Outline the DSM-V diagnosis of schizophrenia
Must be at least one positive symptom
Outline the ICD-10 diagnosis of schizophrenia
Two or more negative symptoms
Test-retest reliability in SZ
If the diagnosis is replicated at another time with the same individual it will result in the same diagnosis
Inter rater reliability
The degree to which experts will arrive at the same conclusion/diagnosis of the same case
Research into diagnosing sz being reliable
Goldstein
Rediagnosed 199 patients using DSM III originally using DSM II
Differences were minimal
85% consistent
Two other experts diagnosed a random 8 from the sample and found same thing
Beck
54% concordance rate between experienced practitioners whereas soderberg reported a concordance rate of 81% suggesting classification systems are more reliable over time
Research into SZ diagnosis being reliable
Read - test retest of schizophrenia had only a 37% concordance when British and American psychiatrists provided a diagnosis based off a case description
69% of Amercians diagnosed sz but only 2% of the British did
Additional AO3 for sz diagnosis
The reliability of SZ diagnosis (81%) is superior to that for anxiety disorders (63%)
Comorbidty - AO1
When someone has two conditions one of them may go undiagnosed
Comorbidity in the classification of sz - AO3
Ophoff assessed genetic material from 50,000 pts
Found that of 7 gene locations on the genome associated with SZ three of them were also associated with bipolar
Suggests a genetic overlap between the disorders
Culture bias in the classification of sz - AO3
Cochrane - people of afroamerican origin are 7x more likely to be diagnosed with SZ when living in britain
Invalid diagnoses are being made
Predictive validity- AO1
Ability to predict future outcomes - ie give a treatment which works
Descriptive validity - AO1
Refers to accuracy and objectivity of information gathered - symptoms must be different from other conditions
Aetiological Validity - AO1
A measure of how similar the cause is for everyone who has the disorder - it should be the same
Predictive validity - AO3
Mason tested four different classification systems to predict the outcome of the disorder in 99 patients
Found that more modern classification systems had better predictive validity
Showing it has improved over time
However Birchwood and Jackson found that 20% of people with sz recover and never have another episode but 10% take their own life,
Too many outcomes for predictable validity to be fully supported
Descriptive Validity - AO3
Jager found it was possible to use the ICD-10 to distinguish patients of sz from persistent delusional disorders, the sz patients had lower overall functioning and more pronounced negative symptoms
High descriptive validity
Aetiological Validity - A03
Bailee surveyed 154 British psychiatrists, they agreed on the influence of genetics and substance abuse etc but still had different views on the exact cause
Culture bias in the validity of sz diagnosis - AO3
Mcgovern and Cope reported that 2/3 of patients of SZ in Birmingham are first or second gen afro caribbeans
This demonstrates overdiagnosis within the black population
Comorbidity in affecting the validity of sz diagnosis
Sim found that 32% of 142 hospitalised people with sz had an additional mental disorder
Symptom overlap in affecting the validity of sz diagnosis
Serper assessed patients with comorbid sz and cocaine abuse, cocaine intoxication on its own and SZ on its own
Although there was considerable symptom overlap in patients with sz and cocaine abuse accurate diagnoses were still mad
General evaluation points for sz diagnosis
May have a negative impact on the individual through creating harmful stigmas, people may become withdrawn to them out of fear of them being insane or dangerous
However it provides people with an explanation their illness is not their fault
Furthermore we can create treatments such as antipsychotics therefore has implications for diagnostic system
