3.2.2 Dopamine Hypothesis Evaluation (Sch) Flashcards
(Genes) many researchers believe dopamine imbalances are caused by what?
Genetic predisposition
(Genes) there is a large body of evidence to support what?
Genetic basis for schizophrenia
(Genes) Gottesman - as genetic similarity between individuals increased what else did?
Their probability of having schizophrenia
(Genes) gottesman - how many times more likely are you to develop schizophrenia if your parent has it vs your cousin?
3x
(Genes) gottesman - if you have an identical twin with schizophrenia what is your risk?
48%
(Genes) gottesman - if your grandparent has schizophrenia what is your risk?
5%
(Genes) gottesman - how many times more likely are you to get schizophrenia if your identical twin has it than if your half sibling does?
8x
(Genes) gottesmans findings suggest there is what?
Genetic factor to schizophrenia and dopamine imbalance
(Genes) what do families share as well as genes?
Environment
(Genes) why is family sharing an environment an issue in investigating genetics?
Hard to separate effects of nature and nurture
(Genes) how can the issue of environment be overcome?
Using adoption studies
(Genes) Heston - who were hestons experimental group?
47 people adopted at birth because their mothers had schizophrenia
(Genes) who did Heston compare them with? What was the purpose of this?
47 matched controls adopted with mentally healthy mothers
Baseline
Ruled out any effect adoption had on developing schizophrenia
(Genes) Heston - the 94 adults were interviewed to see what?
If they developed schizophrenia themselves
(Genes) Heston - of the 47 adults with a biological mother with schizophrenia how many developed it?
5 hospitalised
3 critically ill
(Genes) Heston - how many of the controls developed schizophrenia?
None
(Genes) Hestons research suggest genetics play a role in what?
Development of schizophrenia
(Genes) Tienari - who were the experimental group?
155 adopted children in Finland with biological mothers with schizophrenia
(Genes) Tienari who were they compared to?
Another 155 adopted children with non schizophrenic biological parents
(Genes) Tienari found how many children with a biological mother with schizophrenia developed it?
10.3%
(Genes) Tienari found how many children without a biological parent with schizophrenia developed it?
1.1%
(Genes) what research has been disappointing?
Research looking into one or two genes
(Genes) a group reported how many genetic loci associated with schizophrenia?
108
(Genes)it is too simplistic to say what?
Schizophrenia is caused by a single gene
(Measuring metabolites) what do we use metabolites to measure and why?
Neurotransmitter levels
They are the breakdown products of neurotransmitters
(Measuring metabolites) what is dopamine metabolised into?
HVA
(Measuring metabolites) where can HVA be measured?
Cerebral spinal fluid
By a lumbar puncture
(Measuring metabolites) you would predict patients with positive symptoms would have what levels of HVA and why?
High
Due to high levels of dopamine
(Measuring metabolites) in patients with negative symptoms you would expect what?
Low levels of HVA
(Measuring metabolites) what is found in a lot of research?
High levels of HVA with positive and low with negative
(Measuring metabolites) why is their lack of research?
Due to invasive and unpleasant nature of lumbar puncture
(Measuring metabolites) what can a lumbar puncture be influenced by?
Diet and drugs can affect HVA levels
Individual differences in metabolism
(Serotonin) what does atypical medication block?
Both dopamine and serotonin receptors
(Serotonin) the blocking of serotonin receptors suggests what?
Serotonin plays a role in schizophrenia
(Serotonin) we can not say dopamine is solely responsible for what?
Schizophrenia
(Serotonin) it could be positive symptoms are caused by dopamine and negative?
serotonin explaining the crossover with depression
(Cause or effect) the dopamine hypothesis proposed what?
Dopamine imbalance causes schizophrenia
(Cause or effect) it could be schizophrenia does what?
Causes dopamine imbalances (they are a symptom)
(Cause or effect) what is research using PET scans not able to detect?
Differences in dopamine activity in brains of those with and without schizophrenia
(Cause or effect)it may take time before we know what?
Cause or effect