Topic 2: The Medical Model Flashcards
(37 cards)
Explain the biochemical explanation of depression.
The chemicals in the brain may become imbalanced.
Biochemical explanation of depression: Explain how messages are passed from one nerve cell to another.
Via a synapse. Once the post synaptic cell has been stimulated the serotonin is taken back (reuptake) into the pre synaptic cell to await the next message.
Biochemical explanation of depression: What is the result of low levels of serotonin?
The message might not get passed across the gap before the serotonin is taken back.
Biochemical explanation of depression: What is the role of the SSRI drugs?
It inhibits/prevents the serotonin from being taken back up by the pre synaptic cell & reduce the symptoms of depression.
Explain the biochemical explanation of schizophrenia.
- Overactive dopamine is linked to schizophrenia symptoms.
- Excess dopamine may cause hallucinations.
- Antipsychotic drugs block dopamine receptors.
- This reduces dopamine reaching postsynaptic cells, alleviating symptoms.
Biochemical explanation of schizophrenia: What is treatment aiming to do?
Restoring normal levels of neurotransmitters.
Discuss Gottesman & Shields research regarding the genetic explanation of mental illness.
- MZ twins (identical) had a 58% concordance rate for schizophrenia.
- DZ twins (non-identical) had a 12% concordance rate.
- This suggests a strong genetic influence on schizophrenia.
- However, the 58% concordance in MZ twins indicates that genetics alone do not fully explain the condition.
Explain the evolutionary explanation of mental illness.
- Evolution may have shaped certain fears.
- Fears of spiders, snakes, and heights potentially increased survival.
- Cautious individuals avoided danger, increasing reproductive success.
- These survival-enhancing genes were passed on.
Explain the evolutionary explanation of mental illness: phobias could have a genetic basis.
- Phobias might be inherited survival traits.
- ‘Biological preparedness’ suggests we’re predisposed to fear certain things.
- Öhman’s study showed people learn to fear snakes more easily than neutral stimuli.
- This supports the idea of a biological predisposition to fear evolutionarily relevant threats.
Genetic explanation of mental illness: Treatment
Difficult but we are moving towards genetic manipulation in embryos to reduce physical disorders so maybe at some point this will be used for mental disorders that are shown to have a strong genetic basis.
What the PET scans show?
Differences in brain activity in people with mental illnesses.
What did Brown et al’s research reveal, about brain abnormality as an explanation for mental illness.
In post-mortem studies comparing the brains of patients with schizophrenia against those of patients with affective disorder, the brains of schizophrenics were 6% lighter and had:
- Enlarged lateral ventricles
- Thinner para-hippocampal cortices
What did Weinberger find about identical twins?
Weinberger found MRI differences in the brain structure of identical twins (one with schizophrenia and one without) - these were in the prefrontal cortex and hippocampus volume.
How does Weinberger’s research of identical twins correspond to current evidence?
There is evidence that parts of the brain essential for normal functioning might be damaged in schizophrenic patients
What brain abnormality is associated with depression?
A smaller hippocampal volume than people not experiencing depression.
What might be happening is that people with depression have experienced stress, how would this cause depression?
The release of a stress hormone called cortisol can destroy hippocampal cells. This would mean these cells would then not respond to serotonin as normal - reducing the effect of serotonin in the body.
What did Sheline’s research find?
An elderly women whose depression was in remission that the hippocampus was smaller in these women than it was in other women of the same age.
State 2 treatments to treat mental illness as a brain abnormality.
- Drug therapy
- Surgery (to remove tumours)
Gottesman et al (2010): What was the aim of the research?
To investigate the probability of a child with 2 parents with a psychiatric illness being diagnosed with a mental disorder (in particular the one their parents have).
Gottesman et al (2010): Who were the participants?
- Danish Civil Registration System data was used.
- 2.6 million people were included.
- Couples with both partners diagnosed with schizophrenia or bipolar disorder were identified.
- A control group was included (no parental psychiatric admissions or illness data).
- Mental illness diagnoses in their children (up to age 52) were checked in the same register.
- Diagnoses were based on ICD-8 and ICD-10 hospital discharge records.
- Participants were divided into 4 groups.
Gottesman et al (2010): State the sample size and characteristics of group A.
2 parents with schizophrenia (270), or bipolar disorder (146).
Gottesman et al (2010): State the sample size and characteristics of group B.
1 parent with a diagnosis of either schizophrenia (13,878), or bipolar disorder (23,152)
Gottesman et al (2010): State the sample size and characteristics of group C
Neither parent diagnosed with a disorder (2,239,551)
Gottesman et al (2010): State the sample size and characteristics of group D.
A group of ‘general public’ where there was no data provided about psychiatric illnesses (2,701,593)
