Lesson 4 - Biological Therapies for Schizophrenia

Question 1

What is the main treatment for schizophrenia?

Answer 1

Antipsychotic drugs, taken with tablets, syrup or injections. They are usually given every 2-4 weeks. This is usually followed with psychological therapy

Question 2

What are the two main types of antipsychotic drug?

Answer 2

Typical (first generation) and atypical (second generation)

Question 3

Typical antipsychotics

Answer 3

Been taken since the 1950s, and can include Chlorpromazine.

Strong link to the dopamine hypothesis, believing that SZ is caused by high levels of dopamine.

Typical drugs are dopamine antagonists, reducing the effects of dopamine by binding to dopamine receptors without stimulating them – they block the receptors, reducing the actions of dopamine.

It is also used as a sedative, and calms the nerves of patients with other conditions. It is also more effective as a syrup than a tablet, as it absorbs quicker.

The maximum dosage for this drug is 1000mg.

Question 4

Atypical antipsychotics

Answer 4

Emerged in the 1970s

Used as an improvement on the typical antipsychotics, as it reduces the impact of side effects.

They have a beneficial effect on negative symptoms as well as positive symptoms.

They work in a similar way, but only temporarily occupy D2 receptors but then rapidly disassociate to allow normal dopamine transmission. This minimises the side effects of the drug.

Can include: clozapine, risperidone and olanzapine

Question 5

Clozapine

Answer 5

Atypical drug

Developed in the 60s-70s, but withdrawn due to patients dying from a blood condition called agranulocytosis (severely low levels of white blood cells).

It came back in the 80s as a more effective treatment than typicals. However, patients are regularly blood tested to ensure that they do not have agranulocytosis. Due to this fatal side effect, it is only available as a tablet or syrup, and the daily dosage is much less than chloropromazine (typical).

It works by binding to dopamine receptors but also serotonin and glutamate receptors. By working on other receptors, it helps to reduce depression and anxiety and improves cognitive functioning. Therefore it is usually given to patients at a high risk of suicide. This is important as 30-50% of SZ patients are at risk

Question 6

Risperidone

Answer 6

Atypical drug

Emerged in the 1990s as an attempt to reduce the serious side effects of clozapine while being as effective.

It can be taken as a syrup, injection or tablet, and they are given a dose of about 4-8mg, rising up to 12mg.

It works in a similar way to clozapine with less side effects, therefore smaller doses are required. Evidence suggests it leads to less side effects than most other antipsychotics.

Question 7

Strengths of drug therapy to treat SZ

Answer 7

• There is research evidence to support the moderate effectiveness of typical antipsychotics. Thornley et al (2003) compared the use of chlorpromazine (typical) with a placebo. Data from 13 trials with a total of 1121 ops showed that chlorpromazine was associated with reduced symptoms and better overall functioning. The data from 3 trials of 512 apps showed that relapse rate was also lower when chlorpromazine was taken.
• There is also research to support the appropriateness of atypical antipsychotics. Meltzer (2012) concluded that Clozapine is more effective than typical antipsychotics and other atypical antipsychotics in treating SZ. It was seen as effective in 30-50% of cases where typical antipsychotics failed.
• There is also research evidence to support the fact that relapse rates are much lower with patients who take antipsychotic drugs (both typical and atypical) as opposed to placebos. Leucht et al (2012) carried out a meta-analysis 65 studies, published between 1959-2011 and involving nearly 6000 patients. Some patients were taken off of their antipsychotic medication and given placebos instead. Within 12 months, 64% of those patients who had been given the placebo relapsed, while only 27% relapsed when on antipsychotics.

Question 8

Weaknesses of drug therapy to treat SZ

Answer 8

• There are serious side effects ranging from mild-fatal ones. Typical antipsychotics include side effects like dizziness, agitation, sleepiness, stiff jaw, weight gain and itchy skin, but can also result in neuroleptic malignant syndrome which can lead to high temp, delirium and coma/death. This can occur in 0.1-2% of SZ patients. Even atypical antipsychotics have dangerous side effects, like agranulocytosis.
• Healy (2012) suggests that some successful drug trials have published their results on multiple occasions. Also, because they have a calming effect, antipsychotics appear to be successful, however it does not really show how they reduce symptoms of SZ. Furthermore, most published studies only assess short-term benefits rather than long-term benefits.
• There are ethical issues associated with drug therapy, like consent, and patients may not be in the right frame of mind due to their symptoms to provide fully informed consent.