Biological explanation

Question 1

Genetic research in schizophrenia

Answer 1

Gottesman (1991) - demonstrated a positive correlation between the increasing genetic similarity of family members and their increased risk of developing schizophrenia. Monozygotic twins (48%), dizygotic twins (17%), siblings (9%) and parents (6%).

Question 2

Issue with the concordance rate

Answer 2

It is important to note that there are no 100% concordance rates, therefore demonstrating that there are environmental influences acting on the development of SZ

Question 3

Evidence of biological relationship

Answer 3

Kendler has shown that first-degree relatives of those with schizophrenia are 18 times more at risk than the general population

Question 4

Genetics-Problem of Nature-v-Nurture

Answer 4

It is very difficult to separate out the influence of nature-v-nurture. The fact that the concordance rates are not 100% means that schizophrenia cannot wholly be explained by genes and it could be that the individual has a pre-disposition to schizophrenia and simply makes the individual more at risk of developing the disorder.

Question 5

Genetics-Biologically reductionist

Answer 5

Schizophrenia is a multi-factorial trait as it is the result of multiple genes and environmental factors. This suggests that the research into gene mapping is oversimplistic as schizophrenia is not due to a single gene.

Question 6

what is the Dopamine hypothesis

Answer 6

• Dopamine is a neurotransmitter. It is one of the chemicals in the brain which causes neurons to fire. The original dopamine hypothesis stated that schizophrenia suffered from an excessive amount of dopamine. This causes the neurons that use dopamine to fire too often and transmit too many messages.
• High dopamine activity leads to acute episodes, and positive symptoms which include: delusions, hallucinations, etc.
  lower than usual levels of dopamine in the cortex (outer part of the brain), where less dopamine is being transmitted across synapses. This is linked with negative symptoms, as there is a reducing in normal functioning

Question 7

Evidence to support the genetic explanation

Answer 7

Tienari et al (2004) found that adopted children of biological mothers with schizophrenia were more likely to develop the disorder themselves than adopted children of mothers without schizophrenia, supporting the genetic link

Question 8

Research that goes against the Dopamine hypothesis

Answer 8

Noll (2009) also argues around one third of patients do not respond to drugs which block dopamine so other neurotransmitters may be involved.

Question 9

One criticism of the Dopamine hypothesis

Answer 9

there is a problem with the chicken and egg. Is the raised dopamine levels the cause of the schizophrenia, or is it the raised dopamine level the result of schizophrenia?

Question 10

Neural Correlates

Answer 10

Specific patterns of cortical activity or neural structures which coincide with specific psychological symptoms, and so are assumed to contribute towards those symptoms

Question 11

Neural correlates in schizophrenia

Answer 11

suggest that structures in the brain are associated with the positive and negative symptoms of schizophrenia, such as in the enlarged ventricles found in schizophrenic patients.

Question 12

Research to support Neural correlates - Torrey

Answer 12

• found that in schizophrenia patients, the ventricles in the brain (fluid-filled cavities in the brain that help supply the brain with vital nutrients and eliminate toxins) are 15% larger, meaning that their brains weigh less than those of neurotypical people.
  
  • A link has been found between enlarged ventricles in schizophrenia and loss of grey matter in some brain areas. Grey matter is involved in the control of movements, memories, and emotions. It plays a vital role in normal daily functioning.

Question 13

Research to support Neural correlates -Allen et al

Answer 13

• scanned the brains of patients experiencing auditory hallucinations and compared them to a control group – their task was to identify a pre-recorded voice as belonging to them or someone else.
  
  • They found lower activity in the superior temporal gyrus and the anterior cingulate gyrus in those experiencing hallucinations.

Question 14

Neural correlates- research methods

Answer 14

research into enlarged ventricles and neurotransmitter levels have high reliability. The reason for this is because the research is carried out in highly controlled environments, which specialist, high tech equipment such as MRI and PET scans.

Question 15

Neural correlates- Biologically deterministic

Answer 15

The reason for this is because if the individual does have large ventricles then does it really mean that they will develop schizophrenia?

Question 16

Neural correlates