Schizophrenia: Drug therapy

Question 1

What are the two types of drugs used to treat SZ patients through drug therapy?

Answer 1

• Typical antipsychotics
• Atypical antipsychotics

Question 2

What are typical antipsychotics? (AO1)

Answer 2

Dopamine antagonists:
- E.g. chlorpromazine
- Dopamine antagonists block dopamine receptors in brain synapses, reducing the action of dopamine.
- When initially taking the drug dopamine levels increase, but dopamine production is reduced.
- According to the dopamine hypothesis, dopamine antagonists normalises neurotransmission in key areas of the brain, reducing symptoms like hallucinations

Sedation effect:
- Chlorpromazine is an effective sedative as well as an antipsychotic.
- Often used to calm individuals, with SZ.

Question 3

What are atypical antipsychotics? (AO1)

Answer 3

Clozapine:
- Discovered in the 1980’s to be more effective than typical antipsychotics- marketed as a SZ treatment when other treatments have failed (not 1st treatment choice due to higher risk of fatal blood clotting).
- Blocks dopamine, glutamate and serotonin receptors in brain synapses. Argued to improve depression, anxiety and increase mood.
- Can be prescribed to individuals that are suicidal due to its mood-improving qualities.

Risperidone:
- Newer developed drug in the 1990s- an attempt to produce a drug as effective as clozapine without its side effects.
- Blocks dopamine and serotonin receptors in brain synapses.
- Blocks dopamine receptors much more than clozapine, and so is much more effective and can be used in smaller dosages.
- Evidence SUGGESTS that this leads to fewer side effects than clozapine use.

Question 4

Name the 4 evaluation points for drug therapy to treat SZ:

Answer 4

1) Evidence for effectiveness (S)
2) Serious side effects (L)
3) Mechanism unclear (L)
4) Reason for use (L)

Question 5

Explain evidence for effectiveness (S) as an evaluation point for drug therapy to treat SZ:

Answer 5

• A strength is that there is evidence to support the use of antipsychotics.
• Large body of evidence to support the idea that both typical and atypical antipsychotics are at least moderately effective in treating SZ symptoms.
• Thornley reviewed studies comparing chlorpromazine to control conditions.
• Found that use of chlorpromazine was associated with better overall functioning and reduced symptoms severity compared to the placebo.
• Meltzer found that clozapine is more effective than typical antipsychotics and that it is effective in 30-50% of treatment-resistant cases where typical antipsychotics have failed.
• Suggests that antipsychotics do work for SZ management.

Question 6

Explain serious side effects (L) as an evaluation point for drug therapy to treat SZ:

Answer 6

• A limitation is the likelihood of side effects,
• Typical antipsychotics are associated with a range of side effects e.g. agitation, sleep disturbance, weight gain.
• Long-term use can result in dopamine hypersensitivity, causing involuntary facial movements e.g. blinking, lip-smacking.
• Serious side effects include neuroleptic malignant syndrome (NMS)- where drug use blocks dopamine action in the hypothalamus, causing fatal symptoms such as a high temperature and coma.
  -Suggests that although drug therapy can be beneficial, the risks need to be understood by the patient.

Question 7

Explain mechanism unclear (L) as an evaluation point for drug therapy to treat SZ:

Answer 7

• A limitation is that we do not know how antipsychotics work.
• Our understanding of the mechanism by which antipsychotic drugs work is strongly linked with the dopamine hypothesis- the idea that SZ symptoms are linked to high dopamine activity in the brain.
• However the dopamine hypothesis is not a full explanation for SZ, with some areas of the brain having abnormally low levels of dopamine- meaning that antipsychotics theoretically should not work.
• Suggests that antipsychotics may not be the best treatment for SZ- perhaps some other factor is involved in their apparent success.

Question 8

Explain reason for use (L) as an evaluation point for drug therapy to treat SZ:

Answer 8

• A limitation is that there is an inconsistent reason for antipsychotic use.
• In clinical settings antipsychotics have been prescribed to SZ patients to make them easier for staff to work with (e.g. through the sedative effects of typical antipsychotics), rather than for the benefits of those with SZ themselves.
• However patients themselves may choose to take antipsychotics to calm themselves from the symptoms they experience e.g. distressing hallucinations. This can benefit them through improving their mood and allowing them to mix with others.
• Suggests that there are benefits for using antipsychotic drugs to manage SZ which potentially put the SZ individuals in a vulnerable, exploitative position.