Mental health topic 2 = The medical model Flashcards
Medical models explanation of mental illness list
Biochemical explanation
Genetics explanation
Evolutionary theory
Brain abnormality
What neurotransmitter is associated with depression?
Serotonin - levels too low
Biochemical explanation for depression
Low conc of serotonin means re absorption into presynaptic neurone
So impulse is not transmitted over synaptic cleft
So body cannot respond in appropriate way to stimulation = results in depressive mood
What neurotransmitter is associated with schizophrenia?
Dopamine - levels too high
Biochemical explanation of schizophrenia
Excess dopamine transmitted across synapse = too much reaches post synaptic neurone
Causing positive symptoms of delusions
Treatment based on biochemical explanations of mental illness
Restore normal levels of neurotransmitter action
Depression -SSRIs
Schizophrenia - antipsychotics
SSRIs
Blocks reuptake of serotonin into pre synaptic neurone
So there is enough serotonin to be transmitted in nervous system to carry appropriate response to stimuli, improves depressive mood
What does SSRIs stand for,
Selective Serotonin reuptake inhibitors
Antipsychotics
Treat schizophrenia by blocking receptors to dopamine in post synaptic neurone so no overload of dopamine in nervous system- less positive symptoms
Genetic explanation for mental disorders
Certain alleles of genes may be the cause of mental disorders so can be transferred from parent to child
Gottesman and Shields research into genetics of schizophrenia
If one twin has schizophrenia there is a 58% chance an identical twin with same DNA also has it
But for non identical twin, only 12% chance
Conclusion of Gottesman and Shields research into genetics of schizophrenia
The pass on rate isn’t 100% so causes of mental illness isn’t due to genetics alone
Environmental and individual effects (???)
Evolutionary theory of mental illness: phobias
Over time, humans inherited traits with Evolutionary advantage eg phobia of snakes, spiders etc, enable them to survive, reproduce and be passed on (genetic basis) to children
Less likely to be killed by these things
Who came up with evidence for evolutionary theory of mental illness?
Ohman
Ohman’s research into biological preparedness procedure
Gave participants electric shocks at the same time they saw pictures of snakes/ houses/ human faces
Conclusion of Ohmans research into biological preparedness
Easier to condition a fear response to snakes than houses or human faces suggesting a possible biological predisposition to fear of snakes more as this provides evolutionary advantage
Treatment for genetic explanation of mental illness
Embryo’ DNA manipulation of supposed alleles responsible for physical disorders to reduce their occurrence by using genetic material from parents
could be used for mental disorders in the future?
Research into brain abnormality explanations of schizophrenia
Brown et Al
Weinberger
Brown et Al’s research into brain structure differences in schizophrenia
Post morgen studies on patients with schizophrenia vs affective (mood) disorder
Findings of Browns post mortem research into brains of schizophrenics vs with affective disorder: brain lightness
Brains of schizophrenics 6% lighter Than those with affective disorder
Findings of Browns post mortem research into brains of schizophrenics vs with affective disorder: lateral ventricles
Schizophrenics had enlarged lateral ventricles, (more hollow areas of brain) loss of brain matter linked to auditory processing
Compared to those with affective disorder
Findings of Browns post mortem research into brains of schizophrenics vs with affective disorder: para hippocampal cortices
Significantly thinner in schizophrenics compared to those with affective disorder
Which is involved in episodic memory, visuopatial processing and scene perception (negative symptoms)
Weinberger research into non concordant identical twins with schizophrenia (one has it and other doesn’t)
MRI scans of twins revealed there were differences in prefrontal cortex and hippocampus volume
Research into brain abnormality explanations of depression
Sheline
Main idea behind brain abnormality causing depression
People with depression show a smaller hippocampus volume than people without
How does depression lead to smaller hippocampus volume?
Stress> release of cortisol > destroys cells in hippocampus > neurones can’t respond to serotonin in the normal way > diminished happiness
Shelines research into brain abnormalities in depression
Elderly women who’s depression was in remission that hippocampus is smaller in these women than women who aren’t depressed of the same age
Treatment for mental illness based on brain abnormalities
Drug therapy to reduce effect of brain damage
Surgery in case of a tumour
Application of the medical model
Treatment: Drug therapy (SSRIs)
Brain stimulation techniques
Electro convulsive therapy (ECT)
Transcranial magnetic stimulation (TMS)
Example of drug therapy
Selective serotonin reuptake inhibitors
How do SSRIs work?
Block reuptake of serotonin by presynaptic neurone > greater amount of serotonin in synapse > increases likelihood of enough reaching post synaptic receptor sites > trigger impulse in nervous system to respond appropriately to stimuli
What do SSRIs treat?
Depression, so brain can respond to stimuli associated with happiness more adequately = less depressive mood
How does ECT work,
Electrodes placed on temples > pass electric shock into brain > trigger epileptic seizure to jumpstart brain and relieve symptoms of severe disorder
What disorder does ECT target
Severe depression or psychotic episode
How is ECT administered?
To a patient with electrodes at their temple under anaesthesia
Transcranial magnetic stimulation set up
Electromagnetic coil is held against patients forehead targeting left prefrontal cortex who is alert and awake
Creates a magnetic pulse that travels through skull
How does TMS work
Magnetic pulse creates small electric currents in brain that spread to underlying emotional/ mood regulation structures
Normalise neural networks
What does TMS treat?
Depression
Is SSRI ethical? (Evaluation)
Yes safe for those physically ill (protection from harm)+ few withdrawal effects
No, takes 12 weeks to be fully effective, may put patient at risk in that time
And has side effects eg sexual dysfunction
Evaluate ECT
Unethical has physical health risks eg heart problems
Expensive so not available for all
But yes can be because it’s quick and works
Evaluate TMS
Effectiveness wears off quickly so requires constant treatment and is expensive
