biological therapy for schizophrenia

Question 1

what kind of drugs are typical and atypical antipsychotics

Answer 1

dopamine antagonists

Question 2

give an example of a typical antipsychotic, what is the dose, how can it be taken

Answer 2

Chlorpromazine
can be taken as tablet, syrup or injection.
most dosage is 400-800 mg with injection.

Question 3

which was developed first, typical or atypical drugs

Answer 3

typical drugs

Question 4

outline how typical and atypical drugs work - refer to synapse action

Answer 4

• Dopamine is released by secretory vesicles into the synaptic gap.
• these drugs block the dopamine receptor sites on the post synaptic neuron,
• This means dopamine cannot bind to the D2 receptor site.
• This prevents the neighbouring neuron from reaching an action potential, therefore dopamine is not released.
• Over time this decreases the levels of dopamine in the brain.

Question 5

how were typical drugs developed

Answer 5

developed based on the orgional dopamine hypothesis - schizophrenia is caused by high levels of dopamine.

Question 6

what are the desired effects of chlorpromazine

Answer 6

reduces the effect of positive symptoms (hyperdominergic) by being dopamine antagonists (work to reduce levels of dopamine). however does not worsen negative symtpoms.

Question 7

name 2 atypical drugs

Answer 7

clozapine and risperidone

Question 8

order the drugs from the ones with very severe side effects to those with the least side effects

Answer 8

(worst) clozapine,
chlorpromazine,
risperidone (best)

Question 9

what are the benefits of atypical drugs over typical drugs (AO3)

Answer 9

work on multiple systems not just the dopaminergic system.

Target the neurotransmitters serotonin and glutamate as well as dopamine, which have been found to be implicated in schizophrenia. (mood related neurotransmitters) therefore often prescribed if there is co-morbidity with depression

therefore is more effective at relieving both positive and negative symptoms

Question 10

how is clozapine taken, what is the dosage

Answer 10

taken orally
300-400 mg a day
not available as an injection

Question 11

how is resperidone taken, what is the dosage

Answer 11

tablet, syrup or injection
4-8 mg max 12 mg a day.

Question 12

what is a major limitation of clozapine (AO3)

Answer 12

clozapine can cause serious side effects, for example it can cause blood clots which can be fatal and neuroleptic malignant syndrome - which cause high temp, delirium and coma. As a result patients need regular blood clots and it could be questioned whether the benefits outweigh the cost

Question 13

antipsychotics have been found to be effective for drug resistent patients - outline a study that supports this. (AO3) why might it not fully support

Answer 13

Study by Melzter concluded that atypical antipsychotics were effective in 30-50% of treatment resistent cases where typical antipsychotics have failed.

However a large % were still resistent therefore there are still individual differences in efficacy.

Question 14

what is a limitation of chlorpromazine (AO3)

Answer 14

a large dosage can have a sedative effect as it also affects histamine receptors.
This can be detrimental when used in institutions for example, chlorpromazine has been criticised as a chemical straight jacket as reduced paitents to a calm ‘zombie-like’ state.

while it might be considered necessary to keep patients from harming themselves it could also be thought as dehumanising as they take away individual personality. In addition may be unethical if given to a patient when in a position where they can’t give consent (psychotic state)

Question 15

what is a benefit of resperidone over other antipsychotics (AO3)

Answer 15

much more effective in smaller doses as binds more strongly to dopamine receptors than clozapine. In addition is associated with the lowest number of side effects caused.

Question 16

what is an issue with the understanding of how antipsychotics work (AO3)

Answer 16

the mechinism is unclear, we do not know why they work. For example, the origional dopamine hypothesis suggested schizophrenia is caused by hyperdopaminergia. Therefore antipsychotics should not improve negative symptoms and could make them worse as they are DA antagonists. However atypical drugs improve both positive and negative symptoms therefore the function of these drugs is complex and unlcear.

Question 17

Do drugs deal with the root cause of schizophrenia (AO3)

Answer 17

it is likely the root cause is biology as when drugs stop being taken, the symptoms return, suggesting it was the biology - which was being treated - that caused the symptoms in the first place. However drugs do not lead to a long term behavioural change, as when they stop being taken the symptoms return. Therefore patients have to continuosly take the drugs which is may be unhelpful to individuals who suffer from severe side effects.