schizophrenia - bio: dopamine

Question 1

valid or invalid

Answer 1

Invalid
P: The dopamine hypothesis can be seen as invalid because it doesn’t explain what causes the imbalance of dopamine in the first place, which causes schizophrenia
E: Gottesman et al. (1991) suggests it may be genetic, finding a concordance rate of 48% in Monozygotic twins and 17% in Dizygotic twins. As well as this, research in 2014 has since found 108 genetic loci associated with schizophrenia
T: Therefore because the hypothesis cannot explain this, the dopamine hypothesis would seem to be invalid and incomplete and therefore a weak explanation of schizophrenia
COUNTER: It has provided a good baseline of knowledge that scientists used to develop anti-psychotics in order to combat the positive symptoms of schizophrenia, which has seen to be effective in most cases, showing a sense of validity behind what the hypothesis suggests causes schizophrenia.

Question 2

scientific or not

Answer 2

Scientific
P: We can measure dopamine via objective methods
E: such as a lumbar puncture which measures how much HVA (what dopamine is metabolised into) is present in someone’s cerebrospinal fluid
T: Therefore this is a strength because people view the hypothesis as being more credible and valid
COUNTER: Diet + drugs affect metabolite levels meaning individual differences may vary levels of HVA, therefore decreasing the reliability of using a lumbar puncture

Question 3

reductionist or holistic

Answer 3

Reductionist
P: it’s reductionist because it doesn’t consider other neurotransmitters that may also be involved in schizophrenia
E: Carlson (2000) suggests that low levels of glutamate may cause high levels of serotonin which causes high levels of dopamine. This is supported by the fact that Atypical anti-psychotics block D2 receptors sites AND serotonin 5-HTCA receptor sites
T: therefore it suggests that the dopamine hypothesis is too oversimplified