Biological Therapies: Drug Treatments

Question 1

Typical antipsychotics: Dopamine antagonists

Answer 1

Typical antipsychotic drugs (e.g. chlorpromazine) have been around since the 1950s

They work by acting as antagonists in the dopamine system and aim to reduce the action of dopamine - they are strongly associated with the dopamine hypothesis

Question 2

Typical antipsychotics: Block dopamine receptors in the synapses

Answer 2

Dopamine antagonists work by blocking dopamine receptors in the synapses in the brain, reducing the action of dopamine

Initially, dopamine levels build up after taking chlorpromazine, but then production is reduced

This normalises neurotransmission in key areas of the brain, which in turn reduces symptoms like hallucinations

Question 3

Typical antipsychotics: Chlorpromazine also has sedation effect

Answer 3

Chlorpromazine also has an effect on histamine receptors which appears to lead to a sedation effect

It is also used generally to calm anxious patients when they are first admitted to hospital

Question 4

Atypical antipsychotics: Newer drugs

Answer 4

The aim of developing newer antipsychotics was to maintain or improve upon the effectiveness of drugs in suppressing the symptoms of psychosis and also to minimise the side effects of the drugs used

Question 5

Atypical antipsychotics: Clozapine acts on dopamine, glutamate and serotonin to improve mood

Answer 5

Clozapine binds to dopamine receptors as chlorpromazine does but also acts on serotonin and glutamate receptors

This drug was more effective than typical drugs - clozapine reduces depression and anxiety as well as improving cognitive functioning

It also improves mood, which is important as up to 50% of people with SZ attempt suicide

Question 6

Atypical antipsychotics: Risperidone is as effective as clozapine but safer

Answer 6

Risperidone was developed in the 1990s because clozapine was involved in the deaths of some people from a blood condition called agranulocytosis

Risperidone like clozapine binds more strongly to dopamine
and serotonin receptors

But risperidone binds more strongly to dopamine receptors and is therefore more effective in smaller doses than most antipsychotics and has fewer side effects