biological explanations of schizophrenia

Question 1

what is the neural correlates explanation of schizophrenia?

Answer 1

those suffering with schizophrenia have structural and/or functional differences in their brain compared to non-schizophrenics

Question 2

what are neural correlates?

Answer 2

are when a measure of the structure or function of part of the brain corresponds with an experience of the patient

Question 3

what are neurons?

Answer 3

the basic building blocks of the nervous system. neurone are nerve cells that process and transmit messages through electrical and chemical signals

Question 4

what is a synapse?

Answer 4

the junction between two neutrons. this includes the presynaptic terminal, the synaptic cleft and the post synaptic receptor site.

Question 5

what is dopamine?

Answer 5

a neurotransmitter that generally has an exitory effect and is linked to the sensation of pleasure

Question 6

what is the dopamine hypothesis?

Answer 6

it believes that there are chemical differences in people which lead to schizophrenic symptoms. several neurotransmitters have been implicated in schizophrenia but the most promising lines of research have focused on dopamine.

Question 7

what are the dopamine levels like in schizophrenics?

Answer 7

dopamine is overactive in schizophrenics, especially in the limbic region of the brain. either more was produced or the nerves were more sensitive to dopamine at normal levels.

Question 8

what is hyperdopaminergia?

Answer 8

having higher levels of dopamine

Question 9

what is hypodopaminergia?

Answer 9

low levels of dopamine activity

Question 10

what is brocas area?

Answer 10

an area of the frontal lobe in the left hemisphere (in most people) responsible for speech production

Question 11

how is hyperdopaminergia and the Broca’s area linked?

Answer 11

hyperdopaminergia has been implicated in another part of the brain called Broca’s area that is thought to be involved in speech production. this may help us to understand the poverty of speech and auditory hallucinations seen in SZ

Question 12

how are abnormalities of dopamine and the prefrontal cortex linked?

Answer 12

dopamine abnormalities (hypodopaminergia) in the prefrontal cortex (thinking and decision making) may cause some negative symptoms of SZ

Question 13

what is the prefrontal cortex?

Answer 13

a region in the frontal lobe which is involved with highest-order cognitive activities, such as the working memory

Question 14

what is the ventral striatum?

Answer 14

major portion of the basal ganglia and functions as part of the rewards system. it includes the nucleus accumbens.

Question 15

what is the neural correlate In the ventral striatum?

Answer 15

it is thought that an abnormality in the ventral striatum may correlate with avoiltion. this involves the loss of motivation. to feel motivated one needs to be able to anticipate rewards. the ventral striatum is thought to be involved in this anticipation. a disruption in its function may play a role in avolition.

Question 16

what is the genetic explanation of schizophrenia?

Answer 16

genes are passed on from parent to offspring (genetic inheritance) that will cause the child to become schizophrenic. it relates to the fact that schizophrenia runs in families.

Question 17

what is the overall likelihood of developing schizophrenia? how does you parents having it impact the chances?

Answer 17

1/100
if one parent has it the probability of you also developing it increases significantly.

Question 18

what is GOTTESMAN (1991) twin study into genetic influences on schizophrenia?

Answer 18

showed that the risk for a particular individual developing schizophrenia is proportional to the amount of genes they share. for MZ twins the risk is 48%, for children with 2 affected parents the risk is 46%, for children with one affected parent the risk is 17%, for grandchildren the risk is 5%

Question 19

what are candidate genes?

Answer 19

studying genetic influence by focusing on one particular gene that is thought to be of interest.

Question 20

what is WEINBERGER ET AL (2002) study on candidate genes and schizophrenia?

Answer 20

reported that a particular candidate gene on chromosome 22 was associated with a near double risk of developing schizophrenia. when abnormal, the gene, COMT, disrupts the levels of dopamine in the frontal lobes of the brain, leading to hallucinations and impairments in the ability to discern reality.

Question 21

is schizophrenia polygenic?

Answer 21

schizophrenia is seemed to be polygenic, as a number of genes (upto 100 have been implicated to date) appear to confer a small increased risk of developing the disorder.

Question 22

AO3: how is ‘supporting evidence for the dopamine hypothesis’ a strength for neural correlates in the biological approach to explaining schizophrenia?

Answer 22

Curran et al. (2014) on action of amphetamines is to release dopamine at central synapses. the symptoms of amphetamine psychosis are similar to paranoid schizophrenia and amphetamines are known to worsen schizophrenia symptoms. therefore this supports the idea that high levels of dopamine are linked to schizophrenia.

Question 23

AO3: how is ‘supporting evidence for the ventral striatum’ a strength for neural correlates in the biological approach to explaining schizophrenia?

Answer 23

Juckel et al (2007) measured the activity levels in the ventral striatum in schozophrenic sufferers and found lower levels of activity than those in the control group. this suggests that in some cases, the ventral striatum has an effect on schizophrenia in individuals.

Question 24

AO3: how is ‘real life application’ a strength for neural correlates in the biological approach to explaining schizophrenia?

Answer 24

this helps us to understand starting points to developing and improving the effectiveness of treatments. for understanding the role that dopamine and other neurotransmitters play in the development in schizophrenia means we can develop drug treatments that can be used to treat it more effectively. this then enables us to create genetic counselling.

Question 25

AO3: how is ‘free will versus determinism’ a limitation to the biological explanation for schizophrenia?

Answer 25

biological explanations of schizophrenia strongly suggest our behaviour is determined by preceding forces and is predictable. this explanation believes that the source of the individuals determinism is biological. this is a strength to the research as it has contributed to our understanding of the debate, and provided us with opportunities to establish causal laws, and this predict and control behaviour.

Question 26

AO3: how is ‘supporting adoption studies’ a strength to the genetic explanation of the biological explanation of schizophrenia?

Answer 26

Tienari (2012) conducted a Finnish adoption study in 1969. adopted-away offspring of biological mothers with schizophrenia, plus a matched control group of 135 adopted-away with a mother not diagnosed with any mental health condition. adoptees ranged from 5-57 and had been adopted before the age of 4. 10% of index adoptees had schizophrenia whereas 1% of the control group developed it.

Question 27

AO3: how is ‘supporting meta analysis’ a strength to the genetic explanation of the biological explanation of schizophrenia?

Answer 27

Ripke et al (2014) =study of previous data from studies of schizophrenia that looked at the whole genome. genetic makeup of 37,000 patients with schizophrenia was compared to 113,000 controls. 108 separate genetic variations found to be associated with an increased risk of schizophrenia. genes that were associated affected the function of neurotransmitters.

Question 28

AO3: how is ‘nature versus nurture’ a limitation to the genetic explanation of the biological explanation of schizophrenia?

Answer 28

with studies of genetics, its very difficult to separate the effects of nature from the effects of nurture. e.g. the children in the adoption studies may’ve been with biological parents for different amounts of time before being adopted. so higher incidence of schizophrenia in index cases could be nurture not nature