4.2 Biological and Psychological Explanations for Schizophrenia

Question 1

What is neural correlates?

Answer 1

Patterns of structure/activity in the brain that occur in coexistence with an experience (may be implicated in the experiences origins)

e.g dopamine in schizophrenia

Question 2

What is dopamine?

Answer 2

A neurotransmitter with an excitatory effect, linked to the sensation of pleasure

Question 3

What are the 3 genetic explanations of schizophrenia?

Answer 3

• Family studies
• Candidate genes
• The role of mutation

Question 4

What have family studies shown about the risk of schizophrenia?

Answer 4

Confirm that the risk of schizophrenia increases in line with genetic similarity

Question 5

What is a candidate gene?

Answer 5

A gene that is associated with the development of a particular disorder/condition

Question 6

Why is schizophrenia polygenic and aetiologically heterogenous?

Answer 6

• Polygenic: involves a number of different genes
• Aetiologically heterogenous: a different combination of factors e.g genetic variations lead to the condition

Question 7

Describe Ripke et al (2014) study into candidate genes

Answer 7

• Combined previous data from genome wide studies of schizophrenia
• Genetic make-up of 37,000 schizophrenics compared to control of 113,000 people
• 108 separate genetic variations associated with increased risk of schizophrenia

Question 8

What is the role of mutation in schizophrenia?

Answer 8

Schizophrenia can have a genetic origin despite having an absence in the family history of the disorder

e.g mutation in parental DNA (due to radiation, poison or viral infection)

Question 9

What did Brown et al (2002) research show about the role of mutation in schizophrenia?

Answer 9

• Positive correlations between paternal age (increased risk of sperm mutation) and risk of schizophrenia
• Increases risk from 0.7% in under 25 to 2% in fathers over 50

Question 10

Describe the original dopamine hypothesis

Answer 10

• Drugs used to treat schizophrenia (antipsychotics) reduce DA
• Therefore, schizophrenia a result of high DA levels (hyperdopaminergia) in subcortical areas of the brain

E.g excess of DA receptors in the subcortex to Brocas area (speech production) may explain schizophrenia symptoms e.g speech poverty

Question 11

Describe the updated version of the dopamine hypothesis

Answer 11

DAVIS ET AL

• Addition of cortical hypodopaminergia (abnormally low DA in brain cortex)
• E.g low DA in prefrontal cortex (responsible for thinking) can explain cognitive problems e.g negative symptoms
• Cortical hypodopaminergia leads to subcortical hyperdopaminergia (both high and low DA levels in different regions are influences in schizophrenia)
• ALSO: attempt to explain the origins of abnormal DA function (HOWES ET AL)
• Both genetic variations + early experiences of stress = more sensitive to hyperdopaminergia and hypodopaminergia

Question 12

AO3 for genetic basis of schizophrenia

Answer 12

1. Research support:
- family studies e.g Gottesman shows risk increases with genetic similarity
- Tienari et al: adoption study, biological children of parents with schizophrenia are at heightened risk even if raised in adoptive family
- twin study by Hilker et al (2018) showed concordance rate of 33% in identical + 7% in non-identical twins

2. Environmental factors:
- include both biological and psychological influences
- biological = birth complications, smoking THC-rich cannabis in teenage years
- psychological = childhood trauma (increases vulnerability to mental disorders)
- Morkved et al: 67% of those with schizophrenia reported at least one childhood trauma compared to 38% for matched control group

Question 13

AO3 for neural correlates of schizophrenia

Answer 13

1. Evidence for dopamine: Curren et al (2004) amphetamines increase DA and worsen schizophrenia symptoms/induce symptoms in those without, ALSO antipsychotic drugs reduce DA activity and reduce symptom intensity, ALSO some candidate genes act on the production of DA/DA receptors

2. Glutamate (L): post-mortem/live scanning studies consistently found raised levels of neurotransmitter glutamate in several brain regions of those with schizophrenia, ALSO several candidate genes for schizophrenia involved in glutamate production/processing, strong evidence for the role of other neurotransmitters

Question 14

Who proposed the updated version of the dopamine hypothesis?

Answer 14

Davis et al

Question 15

What did Howe et al state about the origins of abnormal DA function?

Answer 15

Genetic variations and early experiences of stress (psychological and physical) make people more sensitive to cortical hypodopaminergia and subcortical hyperdopaminergia

Question 16

What were the findings of Gottsmans study?

Answer 16

• Large-scale family study
• As genetic similarity increases so does the probability of sharing schizophrenia
• E.g with a schizophrenic aunt there is 2% chance of developing compared to an increase to 48% for an identical twin

Question 17

What is family dysfunction?

Answer 17

Processes within a family which may be risk factors for both development/maintenance of schizophrenia (e.g cold parenting, expressed emotion)

Question 18

Describe Fromm-Reichmann’s psychodynamic explanation for schizophrenia

Answer 18

• Based on accounts of patients from childhood
• Identified a ‘schizophrenogenic mother’
• Characterised as cold, rejecting, controlling
• This creates a family climate of tension and secrecy
• This distrust later develops into paranoid delusions (ultimately schizophrenia)

Question 19

What was Bateson et al’s double-blind theory?

Answer 19

• Emphasised role of communication style within a family
• Developing child regularly trapped in situations where they fear doing the wrong thing (receive mixed signals from parents)
• The child is punished by a withdrawal of love when they get it wrong
• Leaves them with an understanding of the world as confusing/dangerous
• Reflected in symptoms e.g disorganised thinking/paranoid delusions

Question 20

What is expressed emotion?

Answer 20

The level of emotion (in particular negative emotion), expressed towards a person with schizophrenia by carers/family members

Question 21

What are 3 elements of expressed emotion?

Answer 21

- Verbal criticism of the person (occasionally accompanied by violence)
- Hostility towards the person e.g anger/rejection
- Emotional over-involvement in the persons life (needless self sacrifice)

Question 22

How can expressed emotion worsen/trigger schizophrenia?

Answer 22

• High levels of expressed emotion are a source of stress
• This stress can result in a relapse or trigger schizophrenia in a vulnerable individual (diathesis-stress model)

Question 23

What is a cognitive explanation of schizophrenia + 2 examples?

Answer 23

Dysfunctional thought processing:
- Metarepresentation dysfunction
- Central control dysfunction

Question 24

What is dysfunctional thought processing?

Answer 24

Information processing that does not represent reality accurately and produces undesirable consequences

Question 25

What area of the brain is negative symptoms associated with?

Answer 25

- Reduced thought processing in the ventral striatum

Question 26

What 2 areas of the brain are associated with hallucinations?

Answer 26

- Reduced thought processing in the temporal and cingulate gyri

Question 27

What is metarepresentation?

Answer 27

- The cognitive ability to reflect on thoughts and behaviour. This allows us insight into own intentions/goals (and allows us to interpret the actions of others)

Question 28

What did Frith et al identify?

Answer 28

- 2 kinds of dysfunctional thought processes 1. Metarepresentation dysfunction 2. Central control dysfunction

Question 29

What is central control dysfunction and what does it result in?

Answer 29

- The cognitive inability to suppress automatic responses while we perform deliberate actions - Derailment of thought as each word triggers associations (and cannot suppress automatic response) e.g speech poverty and thought disorder = inability to suppress automatic thoughts + speech triggered by other thoughts

Question 30

AO3 for family dysfunction

Answer 30

**1. Research support:** - Links between family schizophrenia and schizophrenia - Family dysfunction indicated by insecure attachment/exposure to trauma in childhood - Read et al: 69% women and 59% men with schizophrenia have history of physical/sexual abuse - Morkved et al: most schizophrenic adults reported at least one chilhood trauma **2. Explanations lack support:** - Almost no evidence to support importance of traditional family-based theories e.g schizophrenogenic mother/double-blind - Both theories based on clinical observations/informal assessment of mothers personalities - Theories lack systematic evidence, family explanations cannot account for link

Question 31

AO3 for cognitive explanations

Answer 31

**1. Research support:** - Stirling et al: compared performance on range of cognitive tasks e.g stroop test (suppressing the tendency to read words aloud) - Compared 30 schizophrenic people to control group of 30 without schizophrenia - As predicted by Firth's theory, those with schizophrenia took longer (average twice as long to name font colours) - Supports the idea that cognitive processes of those with schizophrenia are impaired **2. A proximal explanation:** - Cognitive explanations only explain proximal origins of symptoms (what is happening now to cause symptoms) - Whereas, distal explanations focus on what initially caused the condition e.g family dysfunction - Unclear/poorly addressed about how genetic variation or childhood trauma may lead to problems with metarepresentation/central control - Cognitive theories alone only provide partial explanations for schizophrenia

Question 32

What are 3 examples of family dysfunction?

Answer 32

- Poor family communication - Cold parenting - High levels of expressed emotion

Question 33

What does metarepresentation dysfunction result in?

Answer 33

- Disrupts our ability to recognise our own actions/thoughts as being carried out by ourselves rather than someone else - Explanation for verbal hallucinations (hearing voices) + delusions e.g thought insertion (having thoughts projected into the mind by someone else)