The Biological Explanation of Schizophrenia (Clinical Psychology) Flashcards Preview

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Flashcards in The Biological Explanation of Schizophrenia (Clinical Psychology) Deck (29)
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1
Q

What is the Dopamine Hypothesis for Schizophrenia?

A

People with sz have higher levels of dopamine in the synapses of the neurones in their brains. Raised levels can be caused by increased release into the synapse.

People with sz may also have increased sensitivity to dopamine

2
Q

Increased dopamine in what areas of the Brain are linked to what Symptoms of Schizophrenia?

A

Increased dopamine in:

  • Mesolimbic pathway (mid brain) = Positive Symptoms
  • Mesocortical pathway (frontal lobe) = Negative Symptoms (Give examples of symptoms)
3
Q

What is the Glutamate Hypothesis for Schizophrenia?

A

Research suggests there are strong links between low levels of glutamate and psychotic symptoms including schizophrenia

4
Q

What research evidence supports the biological explanation of schizophrenia?

A

Randrup + Munkvad, Lieberman

5
Q

What did Randrup and Munkvad find in support of the biological explanation of schizophrenia, and what was a problem with the study?

A

They injected rats with amphetamine, which raises dopamine levels. The rats became more aggressive and isolated. These are similar symptoms to schizophrenia. - Animal studies aren’t generalisable to humans

6
Q

What did Lieberman find which supports the biological explanation of schizophrenia, and what was a problem with the study?

A

75% of those with schizophrenia experienced further symptoms or psychotic episodes after taking dopamine imitators, like amphetamines and methylphenidate - The patients already had schizophrenia, so they won’t vulnerable to the effects of dopamine. This doesn’t necessarily mean that it caused the disorder.

7
Q

What drug research supports the biological explanation of schizophrenia?

A

Amphetamines are dopamine agonists which can cause amphetamine psychosis, which has symptoms similar to positive symptoms of schizophrenia - However it doesn’t show why negative symptoms occur

8
Q

What is an Alternative Theory to the biological explanation of schizophrenia?

A

Some genes are associated with dopamine production and sensitivity are found more in those with schizophrenia. It may be that genes are the cause, rather than the dopamine

9
Q

What Gene is known to possibly link to Schizophrenia?

A

C4 C4 is the for pruning. Excessive pruning can lead to positive symptoms, like hallucinations + delusions. Therefore C4 can possibly lead to schizophrenia

10
Q

What is Pruning?

A

Pruning is when the brain gets rid of information that’s deemed of not being important

11
Q

What is the Genetic Hypothesis for Schizophrenia?

A

The more closely related to family member to the individual with schizophrenia, the higher the chances of developing the disorder

12
Q

What is the Genetic Risk of getting schizophrenia for the General Population?

A

1%

13
Q

What is the Genetic Risk of getting schizophrenia with a Second Degree Relative having it?

A

2.5%

14
Q

What is the Genetic Risk of getting schizophrenia with a First Degree Relative having it?

A

Parent: 3.8% Sibling: 8.7% One Parent: 8.7% Two Parents: 12%

15
Q

What is the Genetic Risk of getting schizophrenia with a DZ twin or MZ twin having it?

A

DZ Twin: 30-40% MZ Twin: 40-50%

16
Q

What Research Evidence supports the genetic explanation of schizophrenia?

A

Gottesman, Tienari, Gottesman’s Family studies

17
Q

How does Gottesman’s study Support the genetic explanation of schizophrenia?

A

Gottesman’s 1991 analysis of twin studies revealed:

  • 48% concordance for MZ twins
  • Only 17% concordance for DZ twins.

Also reported that the concordance rate for identical twins brought up apart was very similar to that for identical twins brought up together

    • However, critics have argued that the twins did not spend all of their childhood apart.
18
Q

How does Tienari’s study Support the genetic explanation of schizophrenia?

A

10.3% of adopted children who had a schizophrenic mother developed schizophrenia.

Only 1.1% of adopted children who did not have a schizophrenic mother developed it

19
Q

How does Gottesman’s family studies Support the genetic explanation of schizophrenia?

A

The risk of developing schizophrenia more closely related to the schizophrenic.

  • If both parents have schizophrenia = 46% chance
  • One schizophrenic parent = 16% chance
  • A schizophrenic sibling = 8% chance
20
Q

What research evidence Challenges the genetic explanation of schizophrenia?

A

Torrey, Wahlberg, Joseph

21
Q

How does Torrey’s study Challenge the genetic explanation of schizophrenia?

A

Torrey argued that many twin studies were inadequate due to small samples and biased allocation of twins and fraternal. (There weren’t equal amounts of MZ and DZ twins).

He reviewed eight studies with representative samples and a reasonably certain allocation of twins and found:

  • Concordance rate of 28% for MZ twins and 6% for DZ twins.

Similarly Joseph 2003 reported from nine studies, finding:

  • Concordance rate of 22.4% for MZ and 4.6% for DZ twins.

This shows that when twins aren’t cherry picked, there is a lower concordance rate.

22
Q

How does Wahlberg’s study Challenge the genetic explanation of schizophrenia?

A

Wahlberg reported additional findings from the study started by Tienari, which show that environmental factors are important. They found the genetic risk of schizophrenia increased significantly if the adoptive family was high in communication deviance (tendency to communicate in unclear and confusing ways

23
Q

What Evidence suggests that schizophrenia due to the Environment, rather than Genes?

A

The higher concordance rate in MZ twins may be due to the fact that MZ twins tend to be more treated more similarly than DZ twins Fewer than 50% of children where both parents have schizophrenia developed the order

24
Q

How does Joseph’s study Challenge the genetic explanation of schizophrenia?

A

The fact that concordance rate increase with genetic relatedness may be because they’re also likely to spend more time together, meaning environmental factors may be influential. Joseph found higher concordance is in fraternal twins than ordinary siblings.

25
Q

What Evidence suggests that schizophrenia due to Our Biology, rather than Genes?

A

Throughout all countries, 1% of people are at risk developing schizophrenia Therefore without any genetic influence, you could still develop schizophrenia

26
Q

What is the Neuroanatomical Theory of Schizophrenia?

A

A lot of research has found that individuals with schizophrenia have enlarged ventricles in the brain

27
Q

Which schizophrenic symptoms are enlarged ventricles associated with?

A

Enlarged ventricles almost associated with negative symptoms of schizophrenia, and also with patients who have the worst outcomes.

28
Q

What research evidence supports the neuroanatomical theory of schizophrenia?

A

Johnstone et al: Compared the CAT scans of schizophrenic patients, and matched controls. They found that those with schizophrenia had significant enlargement in ventricular areas. Giedd et al: Found that patients with early onset schizophrenia showed significant developmental increase in ventricular size throughout a longitudinals study

29
Q

What Criticism is there for the Neuroanatomical Theory of Schizophrenia?

A

It is difficult to identify the cause and effect relationship, as brain abnormality rather than the cause of the illness