Paper 3 - Mental Health 2 - The Medical Model Flashcards
1
Q
what is biochemical principles
A
- focuses on abnormal levels of neurotransmitters - too much or too little
- neurones and synapses - messages are transmitted electrically around the brain and body via neurones. there are around 100bilion neurones in the brain. they link at synapses
- neurotransmitters - information is transmitted chemically at the synapse, the electrical charge in the presynaptic nurone causes neurotransmitters to be released which activates receptors in the postsynaptic neurone. Some neurotransmitters are excitatory and some are inhibitory
- the activation of the subsequent neurones depends on the quantity of the neurontransmitters at the synapse too few and the threshold level is not reached.
2
Q
what is the original dopamine hypothesis for schizophrenia
A
- the original hypothesis suggested that people with schizophrenia produce an eccessive amount of dopamine in the brain, particularly in the limbic system
3
Q
what is the revised dopamine hypothesis for schizophrenia
A
- schizophrenia is not due to the excess production of dopamine, but there is an excessive amount of dopamine receptors at the post synaptic neurone and the receptors are more sensitive than normal
- this means more dopamine is absorbed into the next neurone which leads to an excess of dopamine in various pathways in the brain
- this is particularly the case for the D2 subtype of of dopamine receptors.
- this can occur due to a genetic dysfunction or some form of damage to the brain during development like disease, infection or injury.
4
Q
what are the positive symptoms of schizophrenia
A
- hypofunction - too much dopamine activity - in the mesolimbic pathway.
- This is responsible for motivation, emotion and reward.
- This can explain unusual behaviour and perceptions
5
Q
what are the negative symptoms of scizophrenia
A
- linked to erratic dopamine function in the mesocortical pathway
- this is responsible for executive function (mental health and self regulation)
- this can explain the cognitive deficits and problems with affect experienced during an episode
6
Q
what is the research evidence of the dopamine hypothesis
A
- Philip seeman reported several strands of evidence that provide support for the dopamine hypothesis…
- drugs that increase levels of dopamine increase some positive symptoms like hallucinations
- antipsychotic drigs block dopamine receptors and reduce symptoms
- post-mortems of schizophrenic brains show higher density of D2 receptors than normal brains
7
Q
explain family studies for genetic explanations
A
- the lifetime risk of developing schizophrenia is 1%
- but according to Brain Riley and Ken Kendler the risk is ten times greater for the first degree relatives of a person with schizophrenia.
- This is strong but is not conclusive evidence of genetic cause
- Gottesman illustrates the increased risk that children have for developing it if their parents have that or another disorder
8
Q
explain twin studies for genetic explanations
A
- according to Stephen Glatt a range of twin studies show that the concordance rate for schizophrenia is MZ (identical) twins is about 46% to 53%
- in DZ twins it is about 15%
- However this is a meta analysis
- The Genains were identical female quadruplets had identical genes and they developed the disorder before 24 years.
- But there is also evidence of environmental influences, the father physically abused the girls.
- this shows a interactionist approach
- nature - genes - interacts with nurture - treatment by parents .
- they have a genetic predisposition to the disorder but it is triggered or enforced by the environment
9
Q
explain adoption studies for genetic explanations
A
- The Finnish Adopted Family study by Pekka Tienari found that the lifetime schizophrenia risk for adopted children of biological mothers who has schizophrenia was 9.4%
- but for a biological mother without the disorder the rate is 1.2%
- but adopted families are matched to a child = similar environments not controlled for
10
Q
explain association studies for genetic explanations
A
- the multifactual polygenic model claims that many individual genes each have a small increased risk of schizophrenia
- but in combination, the genetic contribution overall is substantial.
- Stephen Ripke conducted a GWAS comparing genotypes of 36,989 people with the disorder and 113,075 non affected control pps.
- they found that 108 separate genetic variations were associated with schizophrenia
11
Q
explain enlarged ventricles for brain abnormality explanations
A
- people with schizophrenia have enlarged ventricles in their brain.
- There are 4 ventricles in the brain - cavities that hold cerebrospinal fluid which provides nutrients to the brain and protects it from damage
- they have no cognitive function
12
Q
explain reduced grey matter for brain abnormality explanations
A
- enlarged ventricles lead to a reduction in the total amount of grey matter (functional neurones) in the brain, particularly in these areas…
- temporal lobes - loss of grey matter causes auditory hallucinations
- frontal lobes - loss may explain incoherent speech and perceptual disturbance like delusions
- thalamus - loss may lead to auditory and verbal hallucinations
13
Q
explain smaller brain size as a brain abnormality explanation
A
- patients with schizophrenia have a redued overall brain size with less grey matter
- the longer the person has schizophrenia the less grey matter in their beain
- this stops when the patient takes antipsychotic medications, suggesting that grey matter is associated with the disorder
14
Q
explain the research evidence for brain abnormality
A
- Hilleke Hulshoff Pol compared 159 people with schizophrenia with 158 healthy individuals
- there can be up to a 30% increase in the size of the ventricles of patients with schziophrenia.
- larger ventricles means less grey matter in the brain - less functionality in the brain
- Haijma analysed 317 studeies that conducted MRI scans on 100 areas of the brain using 8327 patients.
- patents with schizophrenia have 2.6% smaller brains
- the thalamus were even smaller in schizophrenic people who had not recieved any medication for their condition
15
Q
what is the method of Gottesman’s study on genetic explanations
A
- secondary data from a database of hospital records
16
Q
what is the aim of gotessman’s study
A
- to use a larger sample than previous research to investigate the likely hood of offspring being diagnosed with schizophrenia, bipolar disorder or another disorder if their parents had been diagnoed
17
Q
what is the sample of gottesman’s study
A
- danish civil registration system holds information about all people born in Denmark.
- researchers selected pps born between 1968 and 1997
- The Danish psychiatric Central Rehister contains info about patients admitted based on ICD-8 or ICD-10
- ages 10 or over
- over 3 million people
- group 1 - couples who has both been admitted
- group 2 - couples where 1 partner was admitted
- group 3 - no parents had any mental illness
- group 4 - no data on diagnosis
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Q
what is the procedure of Gottesman’s study
A
- data on each offspring was linked with parents psychiatric history
- using the Civil registration the researchers established who their parents were and if they were on the psychiatric register and idenitified their mental disorder
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Q
what were the results for Gottesman’s study
A
- if both parents had schizophrenia there is a 27.3% chance of the children having it
- if one parents had it there is a 7% change
- if neither parents had it there is a 0.86%
20
Q
what are the conclusions of Gottesman’s study
A
- if both parents have a serious psychological disorder this significtantly increasses the risk of the child developing this disorder
- one parent increases the risk but more increased with 2 parents
- the genetic explanation is supported as the research shows an increase chance of developing a disoder if direct relatives have it
21
Q
what is the diathesis stress model
A
- suggests that people may be predisoppsd to a menrtal health condition and hen a triffer causses the condition to show symptoms
- diathesis - genetic, biological or early childhood experience
- stress - new experience or environmental trigger
- holistic, interactionist approach
22
Q
how does Gotessman’s research explain the medical model
A
- because it is a biological explanation of psychological disorders - genetics
- children had an increased risk of being diagnosed with schizophrenia if their parents had been diagnpsed
- research also demonstrates an increased risk of developing a disorder if parents have any psychological disorder, suggesting that the same genes may underlie a number of disorders
- the relationship is not 100%, suggesting other factors as the cause
- the results are useful for genetic counceling helping people decide on having children
- Gotessman warns against misuse of this data as evidence for eugenics
23
Q
evaluate validity in this topic
A
- large sample in Gottessmans research means it can be generalised
- Gotessman used ICD which is believed to be valid
- however the validity of individual diagnosis depends on many factors, some symptoms may overlap so diagnosis being incorrect
- Seeman pointed out various methods wich proved the dopamine hypothesis
- does schizophrenia cause brain abnormality or does brain abnorality cause schizophrenia. however Karlsgot found the differences of a schizophrenic brain of people at risk in very early stages which suggests the brain abnormalities come first
24
Q
evaluate reliability in this topic
A
- MRI scan reliability is poor (Haijmas study)
- reliability of diagnosis for depression is good using DSMV - Brown found a correlation of 0.67 for different clinicians diagnosing the same person
- Leucht - in a review of 6493 pps using antipsychotics for scizophrenia the relapse rate was 27% throughout the 116 studies showing replication the results = external reliability
25
evaluate socially sensitive research in this topic
* interesting behaviour - 1% of the population develop schizophrenia. However risk increases depending on genetics - Gottesman. this allows development of treatments
* distress - Gottesman's study parental guilt
* policies - eugenics policies - people with disorders are prevented from having children or killed
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evaluate ethics in this topic
* informed consent - no pps in Gotessmans study knew their data was used but data was anonymous
* no direct harm - no pps manipulated but knowledge of increased ridk may be upsetting outside the study
* deception - not telling pps aim Leucht reviewed 116 studies of 6493 pps with schizophrenia, 27% on antipsychotics relapsed vs 64% on placebo - they did not know it was a placebo
* cost benefit analysis -ethical rules broken for a few people vs the benefit on developing and testing new medications and genetic councelling to help large numbers of people make informed decisions and get well
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evaluate nature/nurture in this topic
* nature - schizophrenia caused by genetics gotessman
* nurture - brain abnormalities possibly could be caused by brain damage from accidentsm even cannabis use which could cause enlarged ventricles - Hulshoff
* interactionist - The diathesis stress model proposes a genetic predisposition triggered by a life experience
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evaluate determinism/ freewill in this topic
* biological determinism - Hulshoff study
* Environmental determinism - brain abnormalities can be caused by accidents - Seeman
* freewill - some people teach themselves how to control hallucinations by humming or listening to loud music.
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evaluate reductionism/ holism in this topic
* biological reductionism - Gottesman
* environmental reductionism - brain abnormalities caused by brain damage from illness injury or disease
* holist - diathesis stress theory
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evaluate usefulness of research in this topic
* biochemical explanations have practicl benefit - antipsychotic drugs
* genetic explanations - genetic councelling
* research on genetics and mental illness is socially sensitive and could lead to eugenics policies
31
evaluate sampling bias/ ethnocentrism in this topic
* Gottesman used a large sample so can be generalised to Danish population but not to other cultures
* Gotessmans study from a western culture where mental illness of medicalised and bioloical causes are sought. in non western cultures they may use supernatural causes.
* Leuchts meta analysis of 116 studies of antipsychotics is culture biased from western cltures that seek medical treatments. non western cultures may seek natural remedies or supernatural cures
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what were the ineffective treatments of schizophrenia
* psychosurgery
* electroconvulsive therapy
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* how do antipsychotics work
* neuroleptics
* they are dopamine antagonists because they block dopamine
* they do this by occupying the posy synaptic receptor sites of D2 receptors.
* this reduces activity of the postsynaptic neurone
* reduced dopamine activity means less activity in the mesolimbic pathway
* decreases positive symptoms of schizophrenia
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what are the types of antipsychotics
* first generation antipsychotics were introduced in the 1950s as a tranquilliiser to calm patients down. they were effective at reducing positive symptoms not negative ones, e.g. chlorpromazine
* second generation are newer and more widley used they block dopamine receptors in a gradual way. they also reduce negative symptoms, e.g. clozapine
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how are antipsychotics taken
* drugs are administered in a tablet form or by injection which requires a less frequent dose
* as the drugs change the levels of dopamine levels in the brain to reduce symptoms, it is important that medication is taken regularly to stabalise dopamine levels
* if they stop taking medication they will relapse quickly
* the effect will build up slowly in the brain so the patient will need to take the medication over several weeks before symptoms reduce
36
what is the usefulness, effectiveness and practicalities of antipsychotics
* usefulness - Stephan Leucht concluded that antipsychotic medication reduced relapse rate. With 27% relapsing compared to 64% taking a placebo
* effectivness - clozapine is the most effective drug in terms of reducing hospital admissions and use of other medication. This allows people to function properly and get education/ a job - less expense for NHS and pps not on benefits, are paying taxes and have money to spend in shops etc. (helps the economy).
* practicalities - side effects - the worst side effect is extrapyramidal= tremmors, spasms, jerky movement, slow movements or restlessness. this can be very distressing for the patient. Heres found that 75% of pps had not adhered to their regime within 2 years of being discharged.
37
how to treatments help the economy
* This allows people to function properly and get education/ a job
* less expense for NHS
* pps not on benefits
* pps are paying taxes
* pps have money to spend in shops etc.
* (helps the economy).
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