A level psychology paper 3 - Schizophrenia

What's schizophrenia? (SZ)

It's a serious mental health condition which consists of a person having difficulty distinguishing what is real from what's in their imagination.

Who and where is it seen more in?

- Men rather than women

- In cities rather than countryside

- In working class rather than middle class people

What are the 2 major symptoms for the classification of SZ?

Positive and negative symptoms

What are positive symptoms? give exmaples

symptoms that are added to normal behaviour and they include visual hallucinations, delusions, auditory (hearing voices) delusions somatic feeling

What are delusions and hallucinations?

Delusions - bizarre beliefs that seem real to the person with SZ

Hallucinations - bizarre, unreal perceptions about the environment

What kind of delusions do people with SZ normally have?

- Delusions of persecution - people plotting against them

- Delusions of guilt - that they're responsible for a terrible event

- Delusions of being controlled

What are negative symptoms?

absence of normal or desired behaviour

What are the 2 types of negative symptoms that people with SZ have?

Speech poverty - characterised by the lessening of speech fluency

Avolition - general loss of energy, interest in life, and ability to complete tasks

What does reliability mean in the diagnosis of SZ? and how is reliability assessed?

It refers to consistency of a measuring instrument such as a questionnaire or scale to assess the severity of the schizophrenic symptoms. The reliability could be assessed by inter-rater reliability by seeing whether 2 independent assessors give similar diagnosis. It could also be assessed by test-retest reliability by seeing whether tests used to deliver those diagnoses are consistent over time.

What does validity mean in the diagnosis of SZ?

This refers to the extent that a diagnosis represents something that's real and distinct from other disorders and the extent that a classification system such as ICD and DSM measure what it claims to measure.

What's the ICD classification system ?

a manual used to diagnose in Europe

What's the DSM classification system?

a manual used to diagnose in America

What are the 3 different types of validity? explain them.

Predictive validity - If diagnosis leads to a successful treatment then diagnosis is seen as valid

Descriptive validity - patients with SZ should differ in symptoms from patients with other disorders

Criterion validity - do different procedures lead to the same diagnosis?

What's a strength that supports the reliability of diagnosis of SZ?

P: They have a high research support

E: Osorio et Al found excellent reliability of diagnosis. She found that inter-rater scores 0.97 and test-retest scores of 0.92.

T: This shows that diagnosis of SZ are quite consistent

What's a counter- argument to this strength?

However, this is only true for clinicians that used the DSM manual

How valid are diagnoses of SZ, use a research study?

T: Cheniaux et Al found that agreement between 2 psychiatrists was low.

E: One psychiatrist diagnosed 44 with the ICD and 26 with the DSM whereas the other one diagnosed 24 with the ICD and 13 with the DSM .

P: This shows that the classification and diagnosis of the disorder is lacking in validity and reliability.

What's a counter- argument to this strength?

However it can be sorted if we all use 1 classification system which will increase reliability.

What are all the issues associated in diagnosing SZ?

symptom overlap, cultural bias, gender bias and co-morbidity.

How is symptom overlap an issue?

P: This means SZ shares the same symptoms with other disorders, Bipolar disorder, such as delusions and avolition.

E: Ellason and Ross found that those with dissociative identity disorder has more symptoms of SZ than those diagnosed with SZ.

T: This may mean that maybe our classification of SZ as its own disorder is wrong.

How is cultural bias an issue?

P: In around different parts of the world delusions and hallucinations are perceived as positive things. For example the hearing voices movement

E: Pinto and Jones found that British men of Afro-Caribbean heritage were up to 9 times more likely to receive a diagnosis than white men. But people living in a Afro-Caribbean countries were not more likely so it's not a genetic link.

T: Therefore this shows that symptoms are interpreted differently depending on culture and that our system is culturally biased.

How is co-morbidity an issue?

P - this is the presence of 2 disorders at the same time, if they always occur together are they 2 disorders or 1?

E - Buckley et al concluded that around half of patients with a diagnosis of schizophrenia also have a diagnosis of depression (50%) or substance abuse (47%). Post-traumatic stress occurred in 29% of cases and OCD in 23%

T: Therefore maybe our classification of Schizophrenia as its disorder is invalid

How is gender bias an issue ?

P: Fischer et al found that men are diagnosed more often than women

E: This could be a genetic link or maybe women may have support to mask symptoms better

T: Therefore this implies that maybe our diagnosis is not accurately detecting cases in women and they're potentially missing out on treatment.

What have family studies shown about the genetic transmission of schizophrenia?

Evidence suggests that the closer the biological relationship, the greater the risk of developing schizophrenia.

Is Schizophrenia polygenic and aetiologically heterogenous?

- Yes, it's polygenic as lots of of genes contribute to an increased risk of developing it.

- Yes, it's also aetiologically heterogenous as different combination of genes are implicated in the genes as Ripke et Al found 108 genetic variations associated with schizophrenia.

What's a strength of the genetic biological explanation of Schizophrenia?

P: It has a high research support from Tienari's adoption study

E: This is because he had an experimental group where he identified adopted away offspring whose mothers were diagnosed with schizophrenia an a control group of offspring whose mothers has no mental disorders. It was found that 7% of the experimental group ended up developing Schizophrenia compared to only 1.5% of the control group who did.

T: Therefore this shows that SZ does in fact have a genetic link

What's a limitation of the genetic biological explanation of Schizophrenia?

P: Identical twins share a 100% of their genes

E: This means it would be expected that the concordance rate for SZ should be 100% if it was purely due to genetics but it's only around 50% .

T: This therefore implies that there's other influences involved which this explanation ignores.

What's another limitation of the genetic biological explanation of SZ?

P: It's quite biologically reductionist

E: This is because it reduces such a complex disorder into a simple concept of genes ignoring cognitive, family explanations which may have a contribution.

T: Therefore this shows that this explanation may be criticised for not taking a holistic approach.

Explain the dopamine hypothesis as a biological explanation for SZ.

The original version suggested that SZ's positive symptoms were due to high levels of dopamine in the subcortex (hyperdopaminergia). For example an excess of dopamine receptors in Broca's area may be responsible for poverty of speech and auditory hallucinations. More recent versions have included hypodopaminergia where low levels of dopamine in the pre-frontal cortex are believed to be responsible for some of the negative symptoms in SZ.

What's a limitation of the dopamine hypothesis?

P: It is difficult to assess brain levels of dopamine in schizophrenics

E: This is because dopamine levels in the brain fluctuate rapidly and are influenced by various factors such as stress, medication...

T: Therefore it would be difficult to carry out studies to find evidence supporting the link between dopamine levels and SZ

What's a strength of the dopamine hypothesis?

P: It's got a high research support

E: This is because drugs that increase the level of dopamine in the brain produce schizophrenic symptoms

T: Therefore this shows that dopamine is involved in the cause of SZ.

What's another limitation of the dopamine hypothesis?

P: Clozapine is the most effective drug at reducing schizophrenic symptoms

E: It acts on serotonin as well as dopamine

T: This shows that SZ may also be due to levels of serotonin not just dopamine