Biochemical
What neurotransmitter is linked to schizophrenia?
Dopamine
What is a family study?
A type of study investigating whether biological relatives of those with a disorder are more likely than non biological relatives to be similarly affected
What percentage of genes do MZ and DZ twins share?
MZ - 100%
DZ - 50%
Idiographic vs Nomothetic
Research into treatments takes a nomothetic approach, to make generalizations about effective treatments based on the large sets of data. This takes a nomothetic approach because the aim is to find a treatment that is likely to work for most people, based on the data available.
What is a neurotransmitter?
What is a twin study?
a type of study that compares sets of twins to analyst similarities and differences. This may include concordance for intelligence or mental disorders. Both MZ and DZ twins are studied, and their concordance rate is compared.
Describe the sample of the Gottesman and Shields study?
57 twins (24 MZ) (33 DZ)
(some had a diagnosis of schizophrenia)
Reductionist
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
What study supports the biochemical explanation of schizophrenia.
Lindstrom et al (1999) it stated that more dopamine receptors present in greater density and quantity in schizophrenics.
What is an adoption?
A type of study looking at the similarities between adopted individuals and their biological parents as a way of investigating the differing influences of biology and environment.
What did Gottesman and Shields find regarding likelihood?
The likehood of developing schizophrenia went from 1% in the general population up to 48% if you have an identical twin with schizophrenia.
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. This suggests that the biological account cannot give a full explanation of the disorder.
Explain the dopamine hypothesis
-the brains of schizophrenics produce more dopamine than normal individuals
-links positives symptoms and schizophrenia
-large increases of dopamine correlated w more hallucinations and delusions
What did Hilker et al. conclude from their twin study in Denmark?
Heritability of schizophrenia was 79%
What were the results of the study?
50% MZ twins had cheated schizophrenic status
and concordance was lower for DZ twins> 9%
Deterministic
If the individual does have excessive amounts of dopamine then does that really mean that they will develop schizophrenia? Suggesting that the dopamine hypothesis does not account for freewill