The Medical Model Flashcards
Biochemical explanation-Major depression-Monamine hypothesis
- low levels of monamines (dopamine, serotonin, noradrenaline) in the limbic system which controls emotions and drives states such as appetite
- serotonine relates other monamine neurotransmitters
-lack of receptor sites ready to receive SEROTONIN, too much is taken back up by re-uptake sites and so little serotonin is transmitted.
Biochemical explanation-Anxiety
- noradrenaline is a stress hormone which increases blood flow, also activating fight or flight.
- normal synaptic function but NORADRENALINE is persistently being activated and released.
Biochemical explanation-Schizophrenia-Dopamine hypothesis
-excessive amount of DOPAMINE receptors which results in increased absorption
Positive symptoms-too much activity is mesolyombic pathway responsible for motivation, reward and emotion.
Negative symptoms- erratic function in the mesocortiyal pathway responsible for metal control and self-regulation.
Biochemical explanation-Phobias
- GABA is an inhibitory neurotransmitter which counterbalanced the excitatory action of GLUTAMATE. It slows neuronal activity to do with memory and learning pathways.
- Those with phobias have reduced GABA- neural firings of glutamate pathways are higher, leading to feelings of anxiety.
Genetic explanation- Phobias
Twin studies- inconsistent
Association studies- so studies carried out on specific phobias to date.
Genetic explanation- Autism
- 2-6%chance that is one child has it, so will their sibling.
- Recent studies suggest it is caused by a rare eugenic variation which is passed on.
Genetic explanation- Depression
Family studies
Twin studies
Adoption studies
Association studies
Family studies-up to 3x more likely if a parent or sibling has depression.
Twin studies-concordance rates for major depression in MZ 30-50% ad DZ is 12-40%-significance.
Adoption studies-depressed adoptee- biological relatives 8x more likely to have depression than adoptive relatives.
Association studies-hSERT gene. People with a short pair of hSERT alleles are less resilient to stress and more likely to respond to stressful events with depressive reactions,
Genetic explanation- Schizophrenia
Family studies
Twin studies
Adoption studies
Association studies
Family studies-1% of population is at risk. This rises to 10% if a first degree relative has schizophrenia. 27.3% likelihood of developing it if both parents have it.
Twin studies- concordance for schizophrenia in MZ if 46-53% but DV is 15%. The greater the concordance implies a strong genetic component.
Adoption studies-Bio mothers who has it was 9.4% and those who didn’t was 1.2% risk.
Association studies- conducted GWAS comparing genotypes-108 separate variation associated with increased risk.
Brain abnormality explanations
Prefrontal cortex
Limbic system
Amygdala
Hippocampus
Prefrontal cortex:behvaioural control, self-control, emotional processing.
Limbic system-processes emotions, stress responses, including:
Amygdala-feelings of fear and sores emotional memories.
Hippocampus-processing memories, responding to stress hormones, associated with memory loss with charged events.
Brain abnormality explanations-Depression
- lower activity in the prefrontal areas and so individuals struggle to find enjoyment.
- smaller hippocampus-25%less grey matter explains the emotionally charged memories in a dysfunctional way.
Brain abnormality explanations-OCD
- Basal ganglia (controls unwanted behaviour) is damaged, explaining repetitive behaviour.
- frontal cortex (controls inhibition) leaves the control and decision hyperactive.
Brain abnormality explanations-Bipolar
-Amygdala is adults is larger than those younger. It controls fear and emotion.
Decreased volume=depressive state
Enlarged volume=manic state
Gottesman (2010)
Method
Cohort study-a group exposed to a particular factor and a comparison group not exposed to that particular factor.
Gottesman (2010)
Samples details
2.6 millions people from Denmark. Parents and their offspring. The sample was obtained from 1970 to 2007 using the ICD 8 and ICD10 on the Psychiatric Central Register.
Gottesman (2010)
Method
Health conditions analysed for heritability were schizophrenia and bipolar. Couples were compared to their children.
Gottesman (2010)
Aim
Following the idea that if there was an increased chance of a child having the same disorder as their parents, what would be the likelihood of transmitting the disorder if both parents had the disorder.
Gottesman (2010)
Results
Schizophrenia both parents, one parent, neither parent
Bipolar both parents, one parent, neither parent
Schizophrenia both parents=27.3%
Schizophrenia one parents= 7%
Schizophrenia neither parent= 0.86%
Bipolar both parents =24.95%
Bipolar one parent =4.4%
Bipolar either parent =0.48%
Gottesman (2010)
Conclusion
Likelihood of having a mental disorder is increased further if both parents have a disorder.
Gottesman (2010)
Application
Advise parents on increased risk but not done as a way of eugenics, it was to identify the risk and help wit the child during their development as a form of prevention.
Biological treatment-Anti-depressants
- type and what do they do
- positives
- negatives
SSRIs- increase flow of serotonin by backing re-uptake sites’ allowing more to transmit across the cleft into the receiving synapse.
+50% to 60% treated saw a difference
+improved mood, apetite, concentration and relives pain
- don’t adress cause (CBT needed)
- 2-4 week to start working
Biological treatment-Anti-anxiety drugs
- 2 types and what do they do
- positives
- negatives
Benzodiazepines-increases action of GABA which calms CNS
Beta blockers-block affects of adrenaline in there CNS, reducing heart rate and decreases blood pressure.
+Benzodiazepines are fast acting 30-90 mins
+beta blockers fast acting within 1 to 2 hours and can be used on demand
- very addictive
- side effects include vertigo, shaking,dizziness
- doesn’t affect emotional symptoms or the cause of the anxiety.
Biological treatment-Anti-psychosis
- what do they do
- positives
- negatives
Block the chemical receptors of dopamine, serotonin and noradrenaline, redoing the positive symptoms.
+clozapine most effective in handling psychosis symptoms
+allows the individual to be treated in community
- only seen to hide symptoms
- side effects lead to reduced adherence: up to 75% had not adhered to the regime two years after discharge (Heres 2006)
