Biological Therapy For SZ

Question 1

What is a defining characteristic of SZ and related disorders?

Answer 1

Psychosis.

Question 2

What are the two ways antipsychotics can be required?

Answer 2

In short term or long term.

Question 3

How can antipsychotics be divided?

Answer 3

Into typical or atypical/ second-generation drugs.

Question 4

How long have typical antipsychotics been around?

Answer 4

Since the 1950s.

Question 5

What is an example of a typical antipsychotic?

Answer 5

Chloropromazine.

Question 6

How can choloropromazine be taken?

Answer 6

As a tablet, injection or syrup.

Question 7

If chlorpromazine is taken orally how often is it administered and what is the maximum mg?

Answer 7

Administered daily up to a maximum of 1000mg although initial doses are smaller and for most people the dosage is gradually increased to a maximum of 400-800 mg.

Question 8

How do typical antipsychotics work?

Answer 8

Acting as antagonists in the dopamine system.

Question 9

What are antagonists?

Answer 9

Chemicals which reduce the action of neurotransmitters.

Question 10

How do dopamine antagonists work?

Answer 10

By blocking dopamine receptors in the synapses of the brain reducing the action of dopamine.

Question 11

According to the dopamine hypothesis what does the dopamine-antagonist effect do?

Answer 11

Normalises neurotransmission in key areas of the brain reducing symptoms like hallucinations.

Question 12

What is a second effect of chlorpromazine?

Answer 12

Sedative.

Question 13

What is chlorpromazines sedative effect been related to?

Answer 13

It’s effect on histamine receptors however it isn’t fully understood how this leads to sedation.

Question 14

What is chlorpromazine often used for?

Answer 14

To calm individuals with SZ and other conditions usually done when patients are first admitted to hospitals and are very anxious.

Question 15

What is absorbed faster?

Answer 15

Syrup which tends to be given when chlorpromazine is used for its sedative purposes.

Question 16

What is the aim of developing new antipsychotics?

Answer 16

Maintain or improve upon the effectiveness of drugs in suppressing symptoms of psychosis and minimise the side effects of drugs sued.

Question 17

When was clozapine developed?

Answer 17

1960s

Question 18

When was clozapine first trialled?

Answer 18

1970s.

Question 19

When and why was clozapine withdrawn?

Answer 19

1970s following the deaths of some patients from a. Blood condition called agranulocytosis.

Question 20

What was discovered about clozapine in the 1980s?

Answer 20

It was more effective than typical antipsychotics and so was re marketed as a treatment for SZ to be used when other treatments failed.

Question 21

What do people taking clozapine have to do regularly?

Answer 21

Have regular blood tests to ensure they aren’t developing agranulocytosis.

Question 22

How is clozapine not available as due to its potentially fatal side effects?

Answer 22

Not available as an injection.

Question 23

What is the daily dosage for clozapine?

Answer 23

300-450mg

Question 24

How does clozapine work?

Answer 24

Binds to dopamine receptors and acts on serotonin and glutamate receptors which is believed to help improve mood, reduce depression and anxiety and improve cognitive functioning.

Question 25

What do the mood enhancing effects of clozapine mean?

Answer 25

It is sometimes prescribed when an individual is at high risk of suicide which is important because 30-50% of people with SZ attempt suicide at some point.

Question 26

Why was risperidone developed?

Answer 26

In an attempt to produce a drug as effective as clozapine but without its serious side effects.

Question 27

How can risperidone be taken?

Answer 27

As tablets, injections which last around 2 weeks or syrups.

Question 28

How is risperidone initially administered?

Answer 28

As a small dose which is built up to a typical daily dose of 4-8mg and a maximum of 12mg.

Question 29

How does risperidone work?

Answer 29

Binds to dopamine and serotonin receptors more strongly than clozapine and is therefore given in smaller doses.

Question 30

What is there evidence to suggest about risperidone?

Answer 30

This leads to fewer side effects than other antipsychotics.

Question 31

Evaluation:
Evidence for effectiveness

Answer 31

There is evidence to support the idea that both typical and atypical antipsychotics are at least moderately effective in tackling symptoms of SZ.
Thornley et al showed data from 13 trials with a total of 1121 ppts showed that chlorpromazine was associated with better overall functioning and reduced symptom severity compared to a placebo.
This shows that antipsychotics work.

Question 32

Counterpoint for evidence of effectiveness

Answer 32

Healy suggested flaws with evidence for effectiveness e.g. most studies are short-term effects only and some successful trials have had data published multiple times exaggerating the size of the evidence base for positive effects.
This means that evidence is less impressive than it first appears.

Question 33

Evaluation
Serious side effects

Answer 33

Typical antipsychotics are associated with a range of side effects such as dizziness.
Long term use can cause tardive dyskinesia which is due to dopamine super sensitivity and causes involuntary facial movements.
The most serious side effect is neuroleptic malignant syndrome which is believed to be caused when drug the drug blocks dopamine action in the hypothalamus.
NMS causes high temperature, delirium and coma and could be fatal.
This means that antipsychotics do harm as well as good

Question 34

Evaluation
unclear how they work

Answer 34

Our understanding of antipsychotics is strongly linked to the dopamine hypothesis however we know that the original dopamine hypothesis isn’t a complete explanation for SZ and the fact that dopamine levels in other parts of the brain are too low rather than too high.
If this is true most antipsychotics should not work.
This means that at least some antipsychotics may not be the best treatment for SZ.