The Medical Model

Question 1

What is the genetic explanation

Answer 1

states that our genes can predispose us to mental disorders

we inherit genes from our parents 50% from our mother, 50% from our father

the heritability of depression is thought to be 0.37 meaning we have a 37% chance of inheriting depression from our parents

Question 2

Evidence from twin studies

Answer 2

Monozygotic twins share 100% of genes whereas Dizygotic twins share 50% twins share 50%.
If MZ twins have higher concordance rate than DZ twins this suggests it has a genetic basis

A study showed that concordance rates for MZ twins for schizophrenia was around 50% but was 15% for DZ twins

A study shows concordance rate for MZ twins for depression was around 30-50% but it was around 12% for DZ twins

Question 3

Evaluation of twin studies

Answer 3

= assumes MZ twins and DZ twins share similar environments and the only difference between the two are that MZ share 100% of genes but DZ share 50%

= however MZ twins are treated more similarly than DZ twins , therefore will be more similar experiences of MZ twins rather than genes, which leads them to having higher concordance rates for mental disorders

= hard to generalise twin studies to wider population as not many twins

Question 4

Evidence from family studies

Answer 4

indicate the closer a persons genetic relatedness to a person with mental illness, the greater likelihood of developing the disorder

1% chance of developing schizophrenia if no relative has it, 6% if sibling has it and it increases

Question 5

Evaluation of family studies

Answer 5

difficult to sperate out the influence of genetics from environment

families share same genes but also same environment, the closer related you are the more time you spend with them

Question 6

Evidence from adoption studies

Answer 6

children who have been adopted are compared to biological parents and adoptive parents

if greater similarity between child and biological parents, suggests genes play a role

A study found more adopted children whose biological mothers had schizophrenia went on to develop it to than than those who didn’t

A study found adopted children who had depression were 8 x more likely to have biological relatives with depression than adoptive relatives

Question 7

Evaluation of adoption studies

Answer 7

usually try place children in families that are similar to biological family

hard to separate out the influence of genes and the environment

most people arent adopted so hard to generalise findings from adoptees to wider population

Question 8

Evidence from association studies

Answer 8

looks at whether certain genes are linked to mental disorder

Genome projects look at entire human genome to see what’s linked

CANDIDATE GENES FOR DEPRESSION
hSERT gene is linked to depression
study found depressed people are more likely to have shortened alleles for hSERT gene

Question 9

Describe biochemical explanation of mental illness

Answer 9

Imbalances in neurotransmitters in brain can lead to mental illness

High levels of neurotransmitter, dopamine, is linked to schizophrenia

Low levels of monoamines (serotonin, noradrenaline, dopamine) are linked to depression

Fluctuating levels of neurotransmitter noradrenaline linked to bipolar disorder eg. high levels linked to mania

Question 10

Describe dopamine hypothesis and schizophrenia

Answer 10

original hypothesis stated people with schizophrenia have too high levels of dopamine

thought they have abnormally high number of D2 receptors which means too much dopamine is absorbed in the post-synaptic neuron

Question 11

Evidence for dopamine hypthothesis

Answer 11

antipsychotic drugs reduce dopamine activity and reduce symptoms of schizophrenia
> high dopamine levels are linked to schizophrenia

amphetamines (crystal meth) are illegal drugs that act as dopamine agonists because they increase dopamine action in brain
> cause hallucinations + delusions

people with parkisons disease have low levels of dopamine and get drugs to raise levels
> develop schizophrenia as side effect

dopamine plays a role in perceptions so if levels are to high this leads to schizophrenic symptoms eg. hallucinations and problems organising thoughts

Question 12

Describe monoamine hypothesis

Answer 12

depression is caused by low levels of a group of neurotransmitters called monoamines

monoamines = noradrenaline, serotonin + dopamine

low levels of serotonin is linked to reduced appetite and low moods

low levels of noradrenaline linked to disrupted sleep patterns and lack of energy

low levels of dopamine can lead to reduced motivation and less interested in pleasure

Question 13

evidence for monoamine hypothesis

Answer 13

in a study patients with depression didn’t take antidepressants for 5 months then had a PET scan

found had significantly higher levels of monoamine oxidase - enzyme that metabolises the monoamines

supports theory that depressed patients have low levels of monoamines

Question 14

Describe brain abnormality explanation of mental illness

Answer 14

Abnormal brain structures can lead to mental illness

smaller prefrontal cortex is linked to bipolar and schizophrenia

a smaller hippocampus is linked to depression

enlarged ventricles are linked with both schizophrenia and bipolar

Question 15

Describe how prefrontal cortex is linked to schizophrenia and BP

Answer 15

Smaller prefrontal cortex leads to disorganised thinking in schizophrenics, > shrinkage causes disorganised thinking in people

Leads to episodes of high and low mood, > smaller causes problems with regulating emotion in people

Question 16

Describe how enlarged ventricles + loss of grey matter is linked with schizophrenia and BP

Answer 16

Enlarged ventricles = fluid filled cavities in brain (towards middle)

Study compared brains of schizophrenics with healthy individuals and found schizophrenics had 30% increase in size of ventricles

Larger ventricles mean less grey matter in the brain > means less functionality in the brain

Less grey matter means :
in temporal lobe (verbal and acoustic memory) causes hallucinations
in frontal lobe (planning + coordination) causes incoherent speech and delusions

Question 17

Describe how smaller hippocampus is linked to depression

Answer 17

Hippocampus = processing memories and responding to stress hormones

Study found hippocampus is significantly smaller in patients with depression (up to 20%)

More severe depression more severe loss of grey matter in hippocampus
> explain why people with depression process emotionally charged memories in dysfunctional ways

Question 18

Describe how activity in amygdala is linked to depression

Answer 18

Amygdala is responsible for feelings of fear and stores emotional memories
> regulates emotions

Study used fMRI on depressed vs healthy patients and found amygdala was more active during resting + activity

Question 19

Evaluation of brain abnormality explanation

Answer 19

many research involves using MRI scans
large variations in the reliability of MRI scans ,especially in smaller regions eg. amygdala
study found low reliability of amygdala measurements between scanning sessions of 0.6 (its small)

Brain abnormality critised for not establishing cause and effect
> hard to determine brain abnormality causes schizophrenia or its just a consequence of it

However its a valid explanation for schizophrenia as scans of those a risk/early stages have differences compared to controls

Question 20

How to compare explanations of mental illness

Answer 20

> reductionist
deterministic
nature nurture

Studies didn’t find 100% concordance rates so not always a genetic factor!

Biochemical = nurture as due to neurotransmitters which are affected by environment (drugs)

Question 21

Jane has stopped going out with friends and no longer enjoys things she used to.
Outline one way medical model might explain Jane’s behaviour

Answer 21

The medical model could offer biochemical explanation of Janes behaviour

Jane may have imbalances in neurotransmitters in Brian causing her to have low energy

+ low levels of monoamines can be linked to depressive symptoms (explain each one)

Question 22

Aim , Sample , Groups in Gottesman et al

Answer 22

AIM - to see whether having two parents with schizophrenia or bipolar disorder increases chance of developing a mental disorder compared to one parent/ non at all

SAMPLE - 2.7 million offspring plus parents off Danish civil register in 2007

1. couples who had both been admitted to psychiatric hospital + offspring
2. couples where only one patner had been admitted + offspring
3. neither parents had any mental ilness
4. no data on diagnosis

Question 23

Procedure of Gottesman

Answer 23

Secondary data from Danish Civil Registry and Danish Psychiatric Register

Danish psychiatric register - based on ICD identify diagnosis of schizophrenia, bp, depression

Civil register - establish parents, linked offsprings psychatric history to parents to see if genes are a risk factor

Question 24

Results + of Gottensman’s

Answer 24

For both schizophrenia and biopolar the risk of mental illness was much greater if offspring had 2 parents with mental disorder

= 27% offspring with both paretns diagnosed with schizophrenia had it by 52
= 1% for diagnosis by 52 if neither parent

= risk increased when other mental illness was included to 67%

Question 25

Conclusions of Gottesman

Answer 25

Having one parent with a mental disorder increases the child’s risk of developing (other disorders too)

Genes predispose someone to mental illness. However, environmental factors can affect the development of mental disorder too.
The relationship between genes and mental disorder is not 100%, which indicates other factors are important in developing mental disorders

Understanding risks of developing mental disorders can be used by genetic counsellors to inform personal decisions regarding marriage, adoption, health insurance

Question 26

Explain what key research Gottesman et al tells us about mental disorders [5]

Answer 26

suggests there is a genetic basis for mental disorders

investigated seeing whether there is a relationship between parents having a mental disorder + offspring having one

found for schizophrenia + bipolar the risk is greater when two parents had diagnosis - 27% compared to 1% with no parents

gottesman didn’t find 100% concordance rate and suggested environmental factors also play a part in development of mental disorders

Question 27

Usefulness of Gottesman

Answer 27

lead to family planning advice and genetic counselling for parents with mental disorders

found if both parents had mental disorder, the greater chance their children would

however, only used danish register for hospital admissions to identify those with mental disorders

this meant they only looked at severe mental disorders, people with mild disorders may be less likely to pass on genes, so gottesman overstated how much genes for mental disorders are passed down

Question 28

Reliability & Validity of Gottessman

Answer 28

RELIABILITY
= secondary data from Danish civil register and psychiatric register
= replicable and reliable as another researcher could look at registers and replicate findings easily

VALIDITY
= used Danish psychiatric register which shows admissions to psychiatric hospitals based on diagnosis using ICD
= sometimes bipolar disorder is misdiagnosed as schizophrenia using ICD - diagnoses lacks validity

Question 29

Explain how key research by gottesman contributes to medical model of mental illness [5]

Answer 29

by investigating the extent to which genes play a part in the development of mental disorder

found both schizophrenia and bipolar disorder the risk was greater for offspring where two parents had diagnosis

found 27% of offspring had diagnosis compared to 1% with no parents, supporting genetic explanation of mental illness

however, gottesman didn’t find 100% concordance even if both parents had disorder, suggesting environmental factors also play a part in the development of mental disorders

Question 30

Biological treatment for one specific disorder

Answer 30

Antipsychotic drugs for schizophrenia

Question 31

Describe the biological treatment for one specific disorder

Answer 31

high levels of dopamine is related to schizophrenia - too much dopamine absorbed to next neuron - excess of dopamine in brain

anti-psychotic drugs block dopamine D2 receptors on post-synaptic neuron (dopamine antagonists) so prevent dopamine transmission

high levels of dopamine can cause problems with information processing, so less reduces this eg. disorganised thinking, reducing positive symptoms of schizophrenia

typical antipsychotic drugs = older, and cause severe side effects
atypical antipsychotic drugs = newer, clozapine, few side effects

Question 32

Strengths of biological treatment

Answer 32

EFFECTIVE AT REDUCING POSITIVE SYMPTOMS
eg. hallucinations

Study reviewed patients with schizophrenia and found antipsychotic drugs significantly reduced relapse rates + hospitalisation + compared to placebo medication

Study found clozapine is most effective antipsychotic drug
> newer drugs have less side effects

Cheap and easy to administer

Question 33

Weakness of biological treatment

Answer 33

1) Severe side effects
= 25% suffer from disordered motor movements eg. tremors, tics, slurred speech
= cause people to stop taking drugs (75% stopped after 2 years after discharge from hospital)
= newer drugs still have development of blood disorders, should get regular blood tests

2)Treat symptoms not the cause
= patients can develop a tolerance to drugs. increasing doses are needed for therapeutic effect

Question 34

Discuss ethical considerations concerning a biological treatment of one specific disorder [8]

• describe how antipsychotics can be used for schizophrenia
• name and explain 2 ethical considerations

Answer 34

DESCRIBE - antipsychotic drugs are used for schizophrenia. They block dopamine D2 receptors, reduced activity in postsynaptic neuron, prevents dopamine transmission, reduces positive symptoms eg. hearing voices

RESPOSIBILITY OF CLINICIAN GIVING DRUGS
= protection from harm
= antipsychotic drugs change brain chemistry and result in -ve side effects eg. tremors, blood disorders
= can lead to depressive episodes (reduced dopamine)
= however they take drugs themselves, allowing them to live in a community+manage their symptoms rather hospitalised

RIGHT TO WITHDRAW
= many side effects so should have right to withdraw
= hospitalised patients feel forced to take them despite side effects > powerless
= other treatments eg. CBT, so if had severe side effects this is another option

Question 35

Validity of medical model

Answer 35

GOTTESMAN - ICD-10
= a valid system, but some misdiagnosed, study found 45% of patients with bipolar were misdiagnosed with another disorder
= reduces validity as some people in his study could’ve been misdiagnosed , results aren’t valid

GENETIC EXPLANATION
= twin studies assumption MZ and DZ twins share similar enviro and only difference is MZ 100%, DZ 20% genes
= More similar experiences in MZ twins can lead to higher concordance rate for mental disorders
= Although, separate twin studies easier to asses genes vs enviro, but still shared enviro before separation

FAMILY STUDIES
= difficult to separate influence of genetics from environment
= children more similar to parents as shared environment rather than genes

Question 36

Reliability of medical model

Answer 36

MRI SCANS - BRAIN ABORMALITY
= large variations in reliability of MRI as smaller brain regions eg. amygdala
= study founf low reliability of amygdala measurements between scanning sessions (+0.60)

GOTTESSMAN
= used objective measures - Danish Civil Registry, Psycatric Register
= easy to replicate

Question 37

Sampling bias of medical model

Answer 37

GOTTESSMAN - LARGE SAMPLE
= more generalisable to wider population
= only included patients with hospital admissions for schizophrenia and BPD
= doesn’t include outpatients or those with milder mental illness, so bias in findings

INDIVIDUALIST, WESTERN CULTURE
= mostly ^ looking at biological factors in mental illness eg. brain abnormality, biochemical explanations + genes
= other cultures more focused on social, cultural and spiritual factors as causes of mental illness
= ethnocentric

Question 38

Socially Sensitive Research in relation to medical model

Answer 38

GENETIC EXPLANATION
= genes predispose those to mental illness may have implications of distress to parents with mental illness
= Gottessman suggests genes play a role, could affect how society views people with mental disorders

= positive implications = genetic counsellors helping parents way up risk

= negative implications = eugenic argument
=reproduction should be prevented in groups of people, eg. serious mental illness, because of damage to human gene pool

Question 39

Nature/Nurture debate in relation medical model

Answer 39

EXPLANATIONS
= born with genes that predispose us to mental illness (genetic explanation - MZ + DZ twins concordance rates) NATURE
= biochemical and brain abnormality nature
= however environmental factors affect these eg. brain damage, illegal drugs

GOTTESSMAN
= parents have mental disorder, offspring have higher risk of developing one too
= genes create vulnerability to mental illness (nature)
= didn’t find 100% heritability, so environmental factors play a role in development of disorders too (nurture)

DIATHESIS-STRESS MODEL - interactionist approach
- genes create vulnerability (diathesis) for disorder
- only develops if there is a life experience which triggers it (stress)
- considers a person could be born with genes that predispose them to schizophrenia, but don’t go on to develop it

Question 40

Reduction/Holism in relation to medical model

Answer 40

REDUCTIONISM - all three explanations
genetic explanation - only genes predispose us to mental illness (doesnt consider family, poverty, enviromental pressure)
biochemical explanation - only neurotransmitters
brain abornmality - only abnormal brain structures

LESS REDUCTIONIST as provides three explanations of mental illness (genetic, biochemical, brain abnormality)
STILL REDUCTIONIST as a whole as doesn’t consider psychological of social explanations for mental illness

Diathesis stress model is more HOLISTIC

Question 41

Individual/ Situational debate in relation to medical model

Answer 41

INDIVIDUAL
= individual differences in genes, levels of neurotransmitters brain abnormality can lead to mental illness
= ignores situational factors eg. poverty, family issues

SITUATIONAL
= gottessman didnt find 100% heritability for mental disorders
= environmental factors do play a part in mental illness
= diathesis-stress model

Question 42

Psychology as a science in relation to medical model

Answer 42

SCIENTIFIC
= used scientific methods to investigate how genes, neurotransmitters, brain abnormality are linked to mental disorders

BRAIN ABNORMAILITY
- MRI scans (however +0.60 reliability)
- critised for nor establish cause and effect as it doesn’t prove its the cause of a disorder or just a consequence

GENETIC EXPLANATION
= twin studies, adoption studies and family studies provide quantitative, objective data to the extent genes predispose
= twin 100% MZ higher concordance rate
= adoption+twin less scientific (cause and effect)
= association studies scientific - objective methods

BIOCHEMICAL EXPLANATION
=relies on research that makes inferences about levels of neurotransmitters in brain (less scientific)
= depressed patients had more monoamine oxidase than control group, but no reliable rests to diagnose chemical imbalance in brain
= doctors to blood tests to chemicals, but that it, so less scientific

Question 43

Usefulness of medical model

Answer 43

BIOCHEMICAL LED TO DRUG TREATMENTS
= imbalances in neurotransmitters in brain, so drugs rebalance these
= antipsychotic drugs to reduce dopamine transmission
= antidepressant drugs to raise serotonin levels

GENETIC USEFULL
= association studies identifies genes linked to mental disorders
= genetic testing can determine risk of mental illness, help diagnosis, decide medication
= gottessman found 27% children with both parents with disorder more got diagnosed
= led to genetic counselling to assess risk of children + offer advice using his results

Question 44

Free will/determinism in relation to medical model

Answer 44

DETERMINISTIC
= mental illness determined by neurotransmitters, genes, brain structure which is beyond personal control
= gottessman’s results
= small hippocampus linked to depression

FREE WILL
= people choose treatments eg. antidepressants can rebalance neurotransmitters in brain - people exerting free will