Biological therapy for schizophrenia

Question 1

What is an antipsychotic?

Answer 1

Drugs that are used to reduce the intensity of symptoms, in particular positive symptoms of psychiatric disorders like schizophrenia

Question 2

What are the two types of antipsychotic?

Answer 2

• Typical (traditional)
• Atypical (newer, second generation)

Question 3

Name one typical antipsychotic?

Answer 3

Chlorpromazine

Question 4

How is chlorpromazine adminstered?

Answer 4

it can be taken as tablets, syrups or injection and adminstered daily up to a maximum of 1000mg
- The usual dosage is smaller initially and increases to a max of 400-800 mg a day
- prescription has declined over the last 50 years

Question 5

How does chlorpromazine work as a dopamine antagonist?

Answer 5

• It works through the dopamine hypothesis and is an antagonist in the dopamine system
• Antagonists reduce the actions of a neurotransmitter in the brain
• Dopamine antagonists work by blocking dopamine receptors in the synapses of the brain, reducing the action of dopamine

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Question 6

What happens initially when an individual takes chlorpromazine?

Answer 6

• initially, the dopamine levels in the brain
  increase but then its production is reduced

Question 7

What symptoms do antagonists reduce?

Answer 7

• positive symptoms such as delusions and hallucinations

Question 8

What are the additional effects of chlorpromazine?

Answer 8

• It is an effective sedative
• It is related to histamine receptors and can calm individuals down, therefore it is often given to inidviduals who are anxious
• given as a syrup as it works faster

Question 9

Describe atypical antipsychotics.

Answer 9

• They aim to improve the effectiveness of drugs and supress symptoms of psychosis and minimise side effects

Question 10

Name two atypical antipsychotics?

Answer 10

• Clozapine
• Risperidone

Question 11

When was clozapine introduced?

Answer 11

developed in 1960 and introduced in 1970

Question 12

What is the dosage of clozapine?

Answer 12

300 - 450mg

Question 13

What are the negative symptoms of clozapine?

Answer 13

• can cause death by causing agranulocytosis (lack of a specific type of WBC)
• requires regular blood treatments
• not avaliable as an injection due to its side effects

Question 14

How does clozapine work?

Answer 14

• binds to dopamine receptors but also acts on serotonin and glutamate receptots
• can improve depression, anxiety and improve cognitive functioning
• prescribed to people of a high risk to commit suicide

Question 15

When was Risperidone introduced?

Answer 15

1990

Question 16

What is the dosage of Risperidone?

Answer 16

• 4-8mg and a maximum of 12mg
• this reduces side effecrs
• taken as a tablet, injection that lasts for two weeks

Question 17

How does Risperidone work?

Answer 17

• binds to dopamine and serotonin receptors
• binds stronger than clozapine and is more effective in smaller doses
• There is evidence that it also leads to less side effects than other antipsychotics

Question 18

What is a strength of biological therapies?

Answer 18

• There is evidence for their effectiveness
• There is large evidence to support that typical and atypical antipsychotics are moderately effective at tackling the symptoms of schizophrenia
• Thornley reviewed studies that compared the effects of chlorpromazine to control conditions
• Data from 13 trials with 1121 participants found that chlorpromazine was associated with better overall functioning and reduced symptom severity compared to placebo
• Meltzer concluded that clozapine is more effective than typical antipsychotics and was effective in 30-50% of cases where typical antipsychotics failed

Counter point = Healy showed serious flaws with evidence for effectiveness. Only short term and positive effects were published. Antipsychotics have a calming effect but this can be misinterpreted as less servere

Question 19

What is a limitation of biological therapies?

Answer 19

• The likelihood of side effects
• Typical antipsychotics can cause dizziness, agitation, stiff jaw and weight gain
• Long term usage can lead to tardive dyskinesia which is caused by dopamine supersensitivity and can cause involuntary facial movements such as grimacing, blinking and lip - smacking
• The most serious side effect is neuroleptic malignant syndrome which is caused when drugs stop dopamine action in the hypothalamus which can cause high temp, comas and can be fatal
• This shows that the drugs may be avoided and can be deadly

Question 20

What is a limitation of biological therapies?

Answer 20

• The mechanism is unclear
• Understanding drugs is linked to the dopamine hypothesis, however this is still incomplete as schizophrenia has been linked to high levels of dopamine in the subcortex of the brain as well as low dopamine levels in other areas
• Therefore, antipsychotics should not work and brings about questions of their effectiveness causing people to opt out of treatment