Schizophrenia - Biological explanations

Question 1

What are 3 AO1 points

Answer 1

Genetic explanations
Neural correlates
Dopamine hypothesis

Question 2

Who looked at Genetic explanations

Answer 2

Gottesmann et al 1991

Johnson et al 1997

Question 3

What did Gottesmann et al 1991 find

Answer 3

found a higher concordance rate for SZ among MZ twins (48%)
MZ share 100% of their DNA
Therefore the increase in concordance rate amongst MZ twins demonstrates that there is a genetic element to schizophrenia

Question 4

What did Johnson et al 1997 find

Answer 4

conducted research on 3 Swedish triplets who all had SZ and found a genetic abnormality on the 15p gene

Question 5

What is SZ considered as

Answer 5

Polygenic caused by many genes

Question 6

what are 3 evaluation points of the Genetic explanation

Answer 6

1. hard to separate genetic from environ as MZ are same sex, same house, same experiences so share both genetic and enviro
2. Not 100% concordance rate + another factor (The diathesis stress model)
3. support for polygenic - Ripke et al 2014 found evidence suggesting 108 genetic variations were associated with SZ including genes which code for dopamine

Question 7

Explain the dopamine hypothesis AO1

Answer 7

Neurotransmitter
Hyperdopaminergia
hypodopaminergia
Abnormal levels of dopamine in both of these areas cause the symptoms of SZ unlike the original version of the dopamine hypothesis which said too much dopamine is the cause of SZ

Question 8

Explain Hyperdopaminergia

Answer 8

High levels in the sub cortex causes speech poverty and auditory hallucinations

Question 9

Explain hypodopaminergia

Answer 9

Low levels in prefrontal cortex is believed to be the cause of negative symptoms of SZ

Question 10

What are three points to support the role of dopamine in the development of SZ

Answer 10

Antipsychotic drugs
Curran et al 2004
lindstroem et al 1999

Question 11

Why does Antipsychotic drugs support the role of dopamine in the development of SZ

Answer 11

works to reduce dopamine in the brain is effective in reducing positive symptoms in 60% of cases if changing the level of dopamine reduces symptoms then is shows that dopamine does play a role

Question 12

Why does Curran et al support the role of dopamine in the development of SZ

Answer 12

Reported that when a person who does not have SZ takes amphetamine (increases dopamine) start experiencing SZ symptoms and someone with SZ has a worse reaction

Question 13

Why does Lindstroem et al 1999 support the role of dopamine in the development of SZ

Answer 13

Reported that chemicals responsible for the production of dopamine are taken up faster in the brains of SZ patients leading to increased levels of dopamine

Question 14

give 2 AO3 points which don’t support the dopamine hypothesis

Answer 14

Antipsychotic drugs - 40% symptoms did not improve if high levels of dopamine were the only cause of SZ then it would be 100% effective
low research into low levels of dopamine in the cortex cause negative symptoms

Question 15

Explain neural correlates with three key phrases

Answer 15

brain activity linked with symptoms
Avolition + ventral striatum
Hallucinations + superior temporal gyrus

Question 16

Explain the phrase brain activity linked with symptoms in regard to neural correlates

Answer 16

Neural correlates are measurements of the structure of function of the brain that correlate with the + or - symptoms of SZ

Question 17

Explain the phrase Avolition + ventral striatum in regard to neural correlates and use a study

Answer 17

Ventral striatum is involved in anticipation of reward(related to motivation)
Loss of motivation ( avolition) in SZ may be explained by low activity levels here

Juckel found a - correlation between Ventral striatum activity and overall - symptoms

Question 18

Explain the phrase Hallucinations + superior temporal gyrus in regard to neural correlates using a study

Answer 18

Allen et al (2007) found that patients experiencing auditory hallucinations recorded lower levels of activation in the superior temporal gyrus and anterior cingulate gyrus

Question 19

Give a limitation of neural correlates

Answer 19

correlation - causation as is remains in question whether it is unusual activity in the brain causes symptoms or if there are other possible explanations for the correlation

Question 20

Explain further correlation-nauseation as a limitation of neural correlates

Answer 20

A - correlation ay suggest that low activity in the ventral striatum causes avolition but it could be that avolition means that less info passes through the striatum resulting in the low activity.
Therefore although neural correlates exits it tells us little about the causes of SZ