Schizpohrenia Flashcards
Classification and diagnosis A01- DSM and ICD
SZ is a type of psychosis is a severe mental disorder in which thoughts and emotions are impaired so that contact is lost with external reality.
-SZ is characterised by positive symptoms which reflect an excess or restoration of normal functioning E.G hallucinations and delusions
-SZ also characterised by negative symptoms which affect a loss of normal functioning E.G speech poverty and avolition
-there are two main classification systems for the diagnosis one the ICD-10 and the DSM-5
-these two main classification systems classify schizophrenia slightly differently as the DSM-5 needs only one positive symptom to be present while the ICD 10 needs two or more negative symptoms.
Classification and diagnosis of SZ - reliability a01
-relability in the context of diagnosing in classifying SZ is ensuring there is consistency in the diagnosis and classification of SZ by different psychiatrists across time and cultures
-The two factors which bring to question the reliability of SZ are cultural differences and inter-rater reliability
-cultural differences: refers to how there are symptoms which would seem acceptable in some cultures and would not receive a diagnosis of SZ
-inter rater reliability: refers to the extent to which two or more mental health professionals arrive at the same diagnosis for the same patients
Co morbidity: refers to the presence of one or more additional disorders or diseases simultaneously occurring with schizophrenia.
Classification and diagnosis- validity A01
-refers to ensuring the patient is receiving the correct diagnosis and SZ has been classified correctly
-two factors bring into questioning the validity are symptom overlap, and gender bias.
Symptom overlap: occur when symptoms of SZ are also found in other disorders E.G delusions and evolution occurring both schizophrenia and bipolar disorder
Gender bias: refers to the differential treatment of males and females in the diagnosis of schizophrenia. The diagnostic criteria may be gender biased or clinicians may base their judgements on stereotypical beliefs about gender.
Classification and diagnosis- AO3 culture bias- RELIABILITY
-a weakness is that research suggests that the reliability of schizophrenia can be affected by culture bias
-Copeland give both US and British psychiatrist a description of patients
-It was found that 69% of the US psychiatrist diagnosed the patient with schizophrenia but only 2% of the British ones administered the same diagnosis
This demonstrates the discrepancies between the two countries in terms of diagnosed and schizophrenia
-Hearing voices is more acceptable in African cultures because of cultural beliefs in communication with ancestors
-However when reported to a psychiatrist from a different culture such as a more western culture these experiences are likely to be seen as irrational which would lead to a diagnosis.
-therefore questioning the reliability of the diagnosis systems put in place.
Classification and diagnosis- A03 validity gender bias
- another issue of the classification and diagnosis is gender bias.
-males are more likely to be diagnosed with Sz than females
-Women appear to typically function better than men be more likely to work and have a good family relations
-This explains why some women have not been diagnosed with SZ when men with similar symptoms might have
-Lauren and Powell got 290 male and female psychiatrist who were selected to read it to case studies of patient’s behaviour and asked to offer their judgement
When the ps were described as males 56% of the psychiatrist gave a diagnosis of SZ whereas one described as female only 20% gave a diagnosis.
-this supports the idea that gender differences in diagnosis exist
-And appears that because we’re in a better functioning it may bias clinicians to underdiagnose SZ in women
-Therefore threatening the validity of the diagnostic system because many people make it incorrect on no diagnosis based on their gender rather than symptoms.
Classification and diagnosis A03 - idc and DSM
-limitation is the low liability of the diagnosis of schizophrenia
-chinziaux at all had two psychiatrists diagnosed 100 patients using the DSM and the ICD
-He found there was poor inter- rater reliability and the findings suggested that the ICD overdiagnosed and the DSM underdiagnosed
-This inconsistency shows is a weakness
Moreover, this study also highlights the issues of validity in the diagnosis
SZ is more likely to be diagnosed in the ICD than the DSM
-A standard way to asses validity is to see if the classification systems arrive at the same diagnosis and this is not true for this study which can have an impact on treatment.
Bio explanations of SZ AO1- genetics
-caused by biological factors like genetics
-It tends to read families with the risk of developing it higher when you have a family member with SZ
-Grossman showed concordance rates increase when you share more genes with the schizophrenic family member
-with 2 SZ parents had concordance of 46%
-With one SZ parent concordance rate of 13%
-With sibling of SZ had a concordance rate of 9%
-e.g MZ twins have 48% chance of developing SZ if the other has it
-whereas general population has 1% chance
- not one gender responsible
- polygenic- requires number of genes to work in combo and a number of factors
- studies show that certain genes are responsible for the cause of SZ e.g the NRG3 gene variants interact with both NRG1 and ERBB4
Bio explanations of SZ AO1- dopamine
-suggests excess of this NS can lead to hallucinations and delusions which are common symptoms of SZ
-hypodopaminergia is an excess of dopamine in the and Broca’s area- responsible for speech production so excess may cause auditory hallucinations
-Central areas which are associated with +ve symptoms of SZ
-hyperdomapineriga is low levels of dopamine in the pre-frontal cortex ( responsible for thinking and decision making)
-Idea, more recently as prefrontal cortex is associated with negative symptoms E.G evolution
-Drugs like amphetamine can act as antagonists which increased dopamine and cause symptoms like hallucinations and delusions
-suffered with SZ are thought to have higher no of D2 receptors resulting in more dopamine binding so more neurones firing
Bio explanations of SZ AO1- neural correlates
- brain structure differences correlate with certain psychological disorders like SZ
- originally evidence was limited to post-mortems who had suffered with SZ
Research now uses non-invasive scanning techniques like FMRI which give pictures of brain in action through magnetic fields
-early research was focused on people with SZ having enlarged ventricles. This is associated with the damage to central brain areas and prefrontal cortex which recent scanning studies have linked the disorder.-research focus on suffers of FZ having enlarged ventricles and these were associated with negative symptoms of SZ such as avolition and speech poverty
-negative symptoms EG avolition one areafthe brain though to be involved is the ventral straitum involved in anticipation
-So logically and abnormality in this area being involved in the development of avolition
+ve symptoms also have neuro correlates
-Alan scanned brained of ps experiencing auditory hallucinations and in compared to control group
-Lower activities in superior Temporal gyrus and anterior syngulate gyrus or found in the hallucination group
Logical to assume reduce activity in these areas the brain is a neural correlate of auditory hallucinations
Bio explanations of SZ AO3- -ve neural, correlation
-evidence in neural is correlational so impossible to establish causation
-It’s possible the SZ symptoms called changes in the brain rather than the other way round
-Also not all patients with SZ have evidence of enlarged brain ventricles and some having enlarged vegetables but do not suffer with schizophrenia
-Weakness makes it difficult to draw further conclusions about role of correlates in cause of SZ so reducing validity of theory and using enlarge vent theory alone to explain SZ is not possible
Bio explanations of SZ AO3- +ve evidence genetic
-Evidence suggesting dopamine plays role in development
- Joseph conducted me analysis of twin studies on SZ and showed much higher concordance rate for MZ twins compared to DZ twins
-MZ share more jeans showing that they clearly is a difficult factor in development of disorder
-Recent studies use blind diagnosis have shown MZ twins that have high concordance rates to
-Could be argued it’s due to environment as twins tend to have similar upbringing
-However research showed this to be unlikely
-teinari looks adoptees whose mothers had schizophrenia compared to control group if I’m more children were diagnosed with SZ when their mother had the disorder compared to the control
-Researchers claim this gave a decisive answer that genetics played role and development of SZ
Evidence leans towards genetic role so bio factor do you have a major part to play in SZ
-Specifically research shows genetics increase the likelihood of development with high concordance rates between those who share more genes
Bio explanations of SZ AO3- +ve drugs and dopamine evidence
-supporting evidence shows that drugs increase dopamine activity can increase SZ symptoms
-Amphetamine is one
-Those are exposed to large doses of one of these drugs can develop hallucinations and delusions which are similar to those experience in an SZ episode
-Characteristics tend to disappear with withdrawal
-Simile evidence from drugs which decrease a level of dopamine
-When individuals take the drugs they have reduction in hallucinations and delusion
-Strengthen the argument for domino hypothesis and provides further support for biological factor
-However it’s biologically deterministic and ignores other factors
-Evidence suggests CBT have higher level of effectiveness in treating schizophrenia as a combat disorder. CBT has been proven to have high success rates suggesting there must be a cognitive course behind SZ and it can’t be solely biological.
Bio explanations of SZ AO3- -ve dompaine
Moncrieff suggests evidence is not conclusive
-Despite drugs increasing dopamine they also affect other NTs
-Thus evidence for the job Me now but this is me like in face validity
-No claims is a strong evidence against the hypothesis argues the antipsychotic drugs do not reduce hallucinations and delusions in one third of people
-In addition, those who have normal dome levels still experienced the symptoms
-Thus blocking the receptors of these people have no little effect
-Suggesting that dopamine cannot be the sole cause+ve symptoms suggested by the hypothesis but maybe by other NTs
