Biological therapies

Discuss biological therapies for schizophrenia: drug therapy (16 marks)

most common treatment for schizophrenia involves...

The use of antipsychotic drugs

Antipsychotics can be divided into...

Typical or atypical antipsychotics

Typical antipsychotics work as...

Dopamine antagonists, for example chlorpromazine

Antagonists are...

Chemicals which reduce the action of a neurotransmitter

Dopamine antagonists work by...

Blocking dopamine receptors in the synapses, reducing the action of dopamine

According to the dopamine hypothesis of schizophrenia this dopamine-antagonist effect...

Normalises neurotransmission in key areas of the brain (Brocas area), reducing symptoms like hallucinations

Atypical antipsychotics were developed with the aim to...

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

Two examples of atypical antipsychotics are...

Clozapine and risperidone

Clozapine...

Binds to dopamine receptors in the same that that typical antipsychotics do, but in addition acts on serotonin and glutamate receptors

It is believed by acting on serotonin and glutamate...

It improves mood and reduces depression and anxiety in patients, and that is may improve cognitive functioning

However, clozapine has a fatal side effect of causing...

A blood condition called agranulocytosis

When people are prescribed atypical antipsychotics (clozapine)...

They have to have regular blood tests to ensure they are not developing agranulocytosis

Risperidone was developed in an attempt to...

Produce a drug as effective as clozapine but without its serious side effects.

What is one strength for biological therapies for schizophrenia?

Evidence shows antipsychotics are moderately effective. Thornley et al (2003) reviewed data from 13 trials and found that chlorpromazine was associated with better functioning and reduced symptom severity compared with placebo.

There is also support for the benefits of atypical antipsychotics. Meltzer et al (2012) concluded that clozapine is more effective than typical antipsychotics and that it is 30-50% more effective in treatment-resistant cases. Therefore the evidence suggests that antipsychotics are reasonably effective.

What is a further strength of biological therapies for schizophrenia?

Real-world application.

Offering drugs can lead to an enhanced quality of life as patients are given independence. This has a positive impact on the economy as patients can return to work and no longer need to be provided with institutional care.

What is one limitation for biological therapies for schizophrenia?

One limitation of typical antipsychotics is the side effects. Older typical antipsychotics work to block dopamine receptors in the brain to reduce symptoms of schizophrenia.

One of the main negative side effects is Tardive dyskinesia caused by lower dopamine transmission. , involuntary facial movements, and hand movements . This is an unpleasant experience and can also cause patients to be self-conscious and more likely to isolate themselves further.

What is another limitation of biological therapies for schizophrenia?

A further limitation is the side effects of atypical antipsychotics. For example risperidone causes weight gain, which over time can affect a person's cardiovascular health and clozapine can cause a dangerous blood condition called agranulocytosis in some patients. While atypical antipsychotics were developed to reduce side effects, they still do exist which is a serious limitation.