Biological Treatments Flashcards
prefrontal cortex function and role in SZ
function: helps people think logically and organise their thoughts
role: many schizophrenics have lower activity in this area which could be linked to delusions and disorganised thoughts
visual cortex & auditory cortex
function: process info received from the eyes and the ears
role: SZs have the same activity in these areas when they hallucinates as sane people do when they have genuine visual and auditory experiences
basal ganglia
function: located deep inside the brain and affects movements and thinking skills
role: this structure is larger in SZ which could cause motor dysfunction
amygdala
function: responsible for basic feelings such as fear, lust and hunger
role: smaller in SZ patients so can link to loss of emotion
dopaminergic circuits
function: responsible for feelings of pleasure and also affects thinking and movement
role: LOW levels = linked to negative symptoms
HIGH levels = linked to positive symptomd
what is the most common treatment for SZ
- antipsychotic drugs (syrups or tablets)
how is medication administered to non-compliant patients
- if the patient is unwilling to have the medicine, they will get injections every 2-4 weeks
- they can be used to stop or prevent psychosis
what are typical antipsychotics
drugs such as chlorpromazine
- around since 1950s
- strongly associated with the dopamine hypothesis
how are typical antipsychotics thought to work
- act as dopamine antagonists
- blocks dopamine receptors
- ‘tightly bound’ to the dopamine receptors
- according to the dopamine hypothesis it should normalise neurotransmission in key areas
- reducing hallucinations
what is the name of a common typical antipsychotic
chlorpromazine
what effect does the typical antipsychotic chlorpromazine have
- sedative
- often used to calm patients
- can cause confusion, lethargy, dizziness and agitation
what is commonly administered acutely as a syrup
- chlorpromazine
- often for when patients are first admitted to hospital and are anxious
what is tardive dyskinesia
typical antipsychotics are liable to produce movement side effects sometimes resembling Parkinson’s disease
whats the problem with typical antipsychotics
the symptoms of Parkinson’s disease are recreated due to tardive dyskinesia and low D2 levels
- this is not wanted or needed for someone with SZ
why were atypical antipsychotics developed
- 1970’s
- to improve the effectiveness of treating negative symptoms and reduce the side effects of typical antipsychotic drugs
name an atypical antipsychotic
clozapine
in what way is the mechanism of atypical antipsychotics similar and dissimilar to typical antipsychotics
unlike typical antipsychotics atypical ones target a range of neurotransmitters
1. binds to and blocks dopamine receptors in the same ways
2. also acts on seretonin
3. acts on glutamate receptors
4. they are ‘loosely bound’ to a variety of receptors
what are the possible side effects of atypical antipsychotics
- agranulocytosis (a blood disorder)
- weight gain
- cardiovascular problems
how is risperidone different to clozapine
- risperidone was developed clozapine was involved in the deaths of some patients from a blood condition called agranulocytosis
- both bind to dopamine and serotonin receptors
what is the key clinical advantage of atypical antipsychotics compared to typical antipsychotics
patients experience fewer side effects related to high D2 blockades
what is a key challenge for the original dopamine hypothesis
D2 blockade cannot explain both subcortical hyperdopaminergia and cortical hypodominergia
in the new dopamine hypothesis what is the role of dopamine in SZ
hypodopaminergia occurs in the prefrontal cortex
AO3 - strength is that the
evidence shows
antipsychotics are
moderately effective
p - moderately effective
e - thornley et al (2003) reviewed data from 13 trials (1121ppts). found that chlorpromazine was associated with better functioning and reduced symptom severity compared to a placebo
e - Meltzer et al.(2012) concluded that clozapine is more effective than typical antipsychotics, and that it is 30-50% more effective in treatment resistant cases
l - antipsychotics are reasonably effective therapies for SZ
PEEL - The effectiveness of antipsychotics has been vigorously challenged
p - vigorously challenged
e - Healy (2012) suggests that many published studies are of short duration only, published multiple times, implying there is more evidence than there is
e - powerful calming effects of antipsychotics may be effective in short term, btu that side effects may occur with more prolonged treatment
l - may not be as strong as it is sometimes reported