Schizophrenia: Biological Explanations for Schizophrenia

Question 1

Name two types of Biological explanations

Answer 1

> Genetic Factors

> The Dopamine Hypothesis

Question 2

Explain family studies in genetic factors of schizophrenia

Answer 2

Family studies find individuals who have schizophrenia and determine whether their biological relatives are similarly affected more often than non-biological relatives. Family studies have established that schizophrenia is more common among biological relatives of a person with schizophrenia, and that the closer the degree of genetic relatedness the greater the risk.

Question 3

Name an example of a family study

Answer 3

Gottesman

Question 4

Give an example of the findings of a Family study

Answer 4

Children with two schizophrenic parents have a concordance rate of 46%, children of on schizophrenic parent 13% and siblings 9%

Question 5

Name a Twin study into genetic factors of schizophrenia

Answer 5

Joseph

Question 6

Describe Joseph’s study

Answer 6

Joseph calculated that the pooled data for all schizophrenia twin studies carried out prior to 2001 showed a concordance rate for monozygotic twins of 40.4% and for dyzygotic twins of 7.4%. More recent methodologically sound studies (e.g. those using blind diagnoses where researchers do not know whether the twin they are assessing is MZ or DZ) have tended to report a lower concordance rate for monozygotic twins.

Question 7

Explain the Dopamine Hypothesis

Answer 7

Dopamine is one of the many different neurotransmitters that operate in the brain. The dopamine hypothesis states that messages from neurons that transmit dopamine fire too easily or too often, leading to the characteristic symptoms of schizophrenia.

Question 8

Name the 3 sources of evidence which highlight the key role played by dopamine in schizophrenia.

Answer 8

> Amphetamines
Antipsychotic drugs
Parkinsons Disease

Question 9

Discuss Amphetmines

Answer 9

This is a drug which is known as a dopamine agonist, stimulating nerve cells containing dopamine causing the synapse to be flooded with this neurotransmitter. Large doses of the drug can cause the characteristic hallucinations and delusions of a schizophrenic

Question 10

Discuss Antipsychotics

Answer 10

They block the activity of dopamine in the brain. By reducing stimulation these drugs eliminate the symptoms, such as hallucinations and delusions. The fact that these drugs alleviated many of the symptoms of schizophrenia, strengthened the case for being a significant contributory factor in this disorder.

Question 11

Discuss Parkinson’s disease

Answer 11

Low levels of dopamine activity are found in people who suffer from Parkinson’s disease, a degenerative neurological disorder. It was found that some people who were taking the drug L-dopa to raise their levels of dopamine were developing schizophrenic symptoms.

Question 12

Evaluate the use of Family studies in genetic factors of schizophrenia

Answer 12

Research has shown that schizophrenia appears to run in families, supporting the argument for a genetic basis for the disorder. However many researchers now accept that the fact that schizophrenia patterns or other factors that have nothing to do with heredity.

Question 13

Give an example of research which supports evaluation of the use family studies

Answer 13

Research on expressed emotion has shown that the negative emotional climate in some families may lead to stress beyond an individual’s coping mechanisms, thus triggering schizophrenia.

Question 14

Evaluate the use of Twin studies

Answer 14

Joseph points out, it is widely accepted that MZ twins are treated more similarly, encounter more similar environments and experience more ‘identity confusion’ than DZ twin. As a result argues Joseph there is no reason to believe that the difference in concordance rates between MZ and DZ twins reflect nothing more than the environmental differences that distinguish the two types of twin.

Question 15

Name a problem for the dopamine Hypothesis

Answer 15

A major problem for the dopamine hypothesis is the fact that drugs to treat schizophrenia by blocking dopamine activity can actually increase it as neurons struggle to compensate sudden deficiency.

Question 16

Name a study which supports the problem behind the dopamine hypothesis

Answer 16

Haracz

Question 17

Describe Haracz’s findings

Answer 17

In a review of post-mortem studies of schizophrenics, found that most of those studied who showed elevated dopamine levels had received anti-psychotic drugs shortly before death. Post-mortem of schizophrenics who had not received medication, on the other hand, showed that these individuals had normal levels of dopamine.