Biological explanations for schizophrenia

Question 1

What do studies for schizophrenia look into?

Answer 1

Genetic similarities and concordance rates between twins and parents

Question 2

What did Gottesman (1991) find?

Answer 2

Did a large scale family study
48% concordance rate with monozygotic twins
17% concordance rate with dizygotic twins
Shows there is a genetic link

Question 3

What is the issue with using twin studies?

Answer 3

There is never 100% concordance rates so there are environmental factors
Hard to separate nature from nurture

Question 4

What do most modern health practitioners accept about schizophrenia?

Answer 4

It is biological in nature

Question 5

What does aetiologically heterogeneous mean?

Answer 5

One combination of factors may cause schizophrenia in one individual and then a different combination would cause it in another individual

Question 6

What did Ripke et al do? (2014)

Answer 6

Large study combining all previous data from genome wide studies of schizophrenia
37,000 patients were compared with 113000 controls

Question 7

What were the findings of Ripke’s study (2014)?

Answer 7

108 separate genetic variations were associated with the risk of schizophrenia

Question 8

What does research show a small amount of genes can do?

Answer 8

Confer a small increased risk of schizophrenia

Question 9

Is schizophrenia polygenic?

Answer 9

It would appear so as it requires a number of different factors to work in combination

Question 10

Which neurotransmitter is thought to play a heavy role in schizophrenia?

Answer 10

Dopamine

Question 11

What might an excess of dopamine in the Broca’s area be associated with?

Answer 11

Speech poverty

Experience of auditory hallucinations

Question 12

What is hyperdopaminergia?

Answer 12

High levels of dopamine

Question 13

What is hypodopaminergia?

Answer 13

Low levels of dopamine

Question 14

What did Goldman-Rakic et al (2004)?

Answer 14

Identified a role for the low levels of dopamine in the prefrontal cortex which is responsible for decision making and thinking in the negative symptoms of schizophrenia

Question 15

What are the neural correlates of negative symptoms?

Answer 15

Avolition involves the loss of motivation and this involves anticipation of reward and areas of the brain are involved in this, such as the ventral striatum

Question 16

What did Juckel et al (2006) measure?

Answer 16

Neural activity in the ventral striatum in schizophrenia and found lower levels of activity than those observed in controls

Question 17

What did Allen et al (2007) do?

Answer 17

Scanned the brains of patients experiencing auditory hallucinations and compared them to the control group whilst they identified pre-recorded speech as theirs or others

Question 18

What did Allen et al (2007) find?

Answer 18

Lower activation levels in the superior temporal gyrus and anterior cingulate gyrus were found in the hallucinations of the group who also made more errors than the control group

Question 19

What three psychologists provide evidence for schizophrenia being biological in nature and a genetic susceptibility?

Answer 19

Gottesman (1991)
Tienari et al (2004)
Ripke et al (2004)

Question 20

What did Tienari et al (2004) find?

Answer 20

Children who are adopted from schizophrenic families are still susceptible

Question 21

What did Curran et al (2004) find?

Answer 21

Dopamine antagonists like amphetamines that increase the levels of dopamine make schizophrenia worse and produce schizophrenic type symptoms in non-sufferers

Question 22

What did Lindstroem et al (1999) find?

Answer 22

they looked at radioactive studies and found that chemicals needed to produce dopamine are taken up faster in the brains of schizophrenia sufferers than controls suggesting that they produce more dopamine

Question 23

Why does the dopamine hypothesis not provide a full explanation for schizophrenia?

Answer 23

Other neurotransmitters are involved

Question 24

What is the issue with the neural correlates argument as an explanation for schizophrenia?

Answer 24

Correlation doesn’t mean causation
The correlation levels of ventral striatum and negative symptoms of Sz may mean that something is wrong in the VS causing the symptoms, or the negative symptoms may mean that less information passes through, resulting in less activity

Question 25

What is the role of mutation in explaining Sz?

Answer 25

Sz can occur in families with no history

Mutation, eg. in sperm cell, could be caused by radiation or a viral infection

Question 26

What did Brown et al (2002) find?

Answer 26

A positive correlation between paternal age and risk of Sz increasing from 0.7% in fathers under 25 to 2% in fathers over 50