biological therapies for SZ

Question 1

What is the biological therapy for SZ?

Answer 1

The most common treatment for SZ is antipsychotic drugs, which can be administered through tablets, syrups and injections. Injections are usually used for those patients who can’t take their medication properly or are at risk of not taking it at all. Some people take the drugs for a short period of time and are cured others may need to take it for a long time maybe even forever. Once they are stable they can be given psychological therapy such as CBT.

Question 2

What are the two types of antipsychotic drugs?

Answer 2

Typical antipsychotics, first generation - Chlorpromazine

Atypical antipsychotics, second generation- Clozapine, Risperidone

Question 3

Typical antipsychotics

Answer 3

They are dopamine antagonists which mean they decrease the amount of dopamine in the brain, they bind and do not simulate dopamine receptors. This reduces the positive symptoms of SZ.

The dopamine hypothesis suggests that high levels of dopamine in certain regions of the brain cause SZ which is why dopamine antagonists are used as they reduce the actions of dopamine reducing positive symptoms of SZ.

Question 4

Chlorpromazine-typical

Answer 4

Made in the 1950s and can be taken through tablets, injection and as a syrup.

It is a dopamine antagonist binding and not stimulating dopamine receptor sites. It is also used as a sedative for other conditions such as for calming peoples nerves.

the maximum dosage is 1000mg but is usually taken in 400-800mg doses that gradually increases.

Question 5

Atypical antipsychotics

Answer 5

Emerged in the 1970s to improve on the effectiveness of typical antipsychotic drugs an minimise their side effects. They also help reduce negative symptoms and cognitive impairment so are suitable for treatment resistant patients.

They work similarly to typical antipsychotic drugs as they block dopamine receptors but they also allow normal levels of dopamine transmission. This is thought to cause the reduction in side effects as new dopamine theories suggest abnormally low dopamine levels can cause SZ as well.

Question 6

Clozapine-atypical

Answer 6

Developed in the 1960s and trailed in the 1970s. A number of patients died from a blood condition that reduced the amount of white blood cells they had so it has withdrawn.

It returned in the 1980s as it was seen as being effective or SZ as typical antipsychotic drugs did not seem to work.

Patients are given regular blood tests to make sure they do not suffer from the blood condition caused by the drug. Due to it’s possibly fatal side effects it is not available as an injection only as a syrup or as tablets. The dosage is much lower then over drugs, only between 350-400mg a day. It binds dopamine, serotonin and glutamate receptors, by working on other neurotransmitters it reduces depression and anxiety while improving cognitive functioning. Due to improving mood it is given to those who have high risks of suicide, this is important as studies show 30-50% of SZ patients are likely to attempt suicide.

Question 7

Risperidone-atypical

Answer 7

Emerged in the 1990s in an attempt to reduce the negative effects of Clozapine while being equally as effective. It can be taken as a tablet, injection or as a syrup. Patients are usually given a dose between 4-8mg a day up to a maximum of 12mg. It also binds dopamine receptors but has less side effects then Clozapine as it is better at it leading to smaller doses.

Question 8

Strengths of drug therapy

Answer 8

• ) Research evidence supports moderate effectiveness of typical antipsychotic drugs in treating SZ. An example is a study that compared the use of chlorpromazine with placebos and found that the drug with more reduced symptoms and better overall functioning. Data from a group of 512 found the relapse rate was lower when using chlorpromazine. This shows antipsychotic drugs where effective in treating SZ.
• ) A study found the atypical drug Clozapine is more effective then typical antipsychotics and other atypical antipsychotic drugs in treating SZ, it had a 30-50% success rate in patients where typical antipsychotic drugs had failed. This shows that drugs are becoming better at treating SZ over time, especially since studies have found mixed results when comparing this drug to Risperidone suggesting that SZ is a complex disorder.
• ) A meta anlysis of 65 studies between 1959 and 2011 involving almost 6000 patients compared both typical and atypical antipsychotic drugs to placebos. with 12 months the relapse rate for those with placebos was 64% for those on antipsychotic drugs it was 27%.

Question 9

weaknesses of drug therapy

Answer 9

• ) Drug therapy has many possible side effects from mild ones to fatal ones. typical ones include dizziness, weight gain and sleepiness while more profound effects include tardive dyskinesia which can lead to involuntary facial movements and NMS which can cause coma and death. This may occur to 0.1-0.2% of SZ patients.
• ) Another weakness is that some effective drug trials have their data published multiple times exaggerating the effectiveness. Antipsychotics also having powerful calming effects so it can seem the drug is successful but it may not actually show how much it reduces symptoms.
• ) Another weakness is that SZ patients suffer from a psychotic disorder so may not be in the right frame of mind to give fully informed consent. This is especially an issue as they can have severe side effects that may be irreversible.