AQA Syllabus focus:
'Drug therapy for schizophrenia, including typical and atypical antipsychotics.'
Drug therapy is the main biological treatment for schizophrenia. AQA expects you to know the difference between typical and atypical drugs, how they act, and their strengths and limitations.
Antipsychotic drug therapy
Antipsychotics are used to reduce the intensity of psychotic symptoms and help patients function more effectively in everyday life. They do not cure schizophrenia, but they can control symptoms, lower relapse risk, and make long-term management easier.
Antipsychotic — a drug used to reduce psychotic symptoms such as hallucinations and delusions, mainly by altering neurotransmitter activity in the brain.
Most antipsychotic drugs affect dopamine, because schizophrenia has long been linked to overactivity of dopamine systems.
However, newer drugs also act on serotonin, which is one reason they are described as atypical.
Typical antipsychotics
How typical antipsychotics work
Typical antipsychotics are the older, first-generation drugs. A key example is chlorpromazine. These drugs mainly work as dopamine antagonists, meaning they block dopamine receptors, especially D2 receptors.
By blocking dopamine activity in the brain, typical antipsychotics reduce the effect of excessive dopamine transmission. This is most closely linked to a reduction in positive symptoms, especially hallucinations and delusions. Chlorpromazine can also have a calming, sedative effect, so it may reduce anxiety, agitation, and disturbed behavior.
Typical antipsychotics are usually taken daily, although some can be given as long-acting injections. They are often effective, but they are most strongly associated with improvements in positive symptoms rather than negative symptoms.
Limitations of typical antipsychotics
A major issue with typical drugs is the range of side effects caused by blocking dopamine in other brain systems, not just the pathways linked to schizophrenia. These side effects can include stiffness, shaking, restlessness, and involuntary muscle movements. These movement-related effects are often called extrapyramidal side effects.
This diagram maps the core basal ganglia motor circuits (direct and indirect pathways) and labels whether each connection is excitatory or inhibitory. It highlights how dopaminergic input modulates these pathways to fine-tune movement, which is why dopamine receptor blockade can lead to parkinsonian-type rigidity/tremor and other extrapyramidal symptoms. Source
Extrapyramidal side effects — movement-related side effects of antipsychotic drugs, such as tremors, muscle rigidity, and involuntary movements.
One serious long-term risk is tardive dyskinesia, involving repetitive, uncontrollable movements, often of the face or tongue. Because these side effects can be distressing, some patients stop taking the medication, which can increase the chance of relapse.
Atypical antipsychotics
How atypical antipsychotics work
Atypical antipsychotics are newer, second-generation drugs. Important examples are clozapine and risperidone. These drugs were developed to treat schizophrenia effectively while producing fewer severe movement side effects than typical antipsychotics.
Atypical drugs still affect dopamine, but they also act on serotonin. Clozapine binds to dopamine receptors less strongly than chlorpromazine and also blocks serotonin receptors. This may help it improve both positive symptoms and, in some cases, negative symptoms. Clozapine is often used when other drugs have not worked, so it is especially important in treatment-resistant cases.
Risperidone also acts on both dopamine and serotonin. It is often used at low doses, where it can be effective with fewer movement-related side effects than typical drugs. At higher doses, however, movement side effects can still occur.
Side effects of atypical antipsychotics
Although atypical drugs generally reduce the risk of severe extrapyramidal side effects, they are not free from problems. Common concerns include weight gain, sedation, and metabolic changes. Clozapine also carries a rare but serious risk of lowering white blood cell count, so patients taking it need regular blood monitoring.
Comparing typical and atypical drugs
The main contrast between the two groups is their receptor action and side-effect profile.
Typical antipsychotics mainly block dopamine and are especially aimed at reducing positive symptoms.
Atypical antipsychotics act on dopamine and serotonin, and they may be more helpful for a wider range of symptoms.
Atypical drugs were designed to reduce the severe movement side effects associated with older drugs.
However, atypical drugs may produce other important side effects, especially weight gain and metabolic problems.
This means the choice of drug is not simple. A medication that works well for one patient may be ineffective or produce unacceptable side effects for another.
Effectiveness and issues in use
Research generally shows that antipsychotic drugs are more effective than placebo for reducing schizophrenia symptoms, especially in the short term. This supports the view that biological processes are important in schizophrenia. Drug therapy can also reduce relapse, which is why antipsychotics are often used as ongoing maintenance treatment.
However, effectiveness is not identical across all drugs. Clozapine is often seen as one of the most effective options for people who do not respond to other antipsychotics. At the same time, claims that all atypical drugs are much better than typical drugs are too simple. Some evidence suggests differences in effectiveness are modest, and benefits must be weighed against side effects.
Another issue is patient compliance. If medication produces unpleasant effects, patients may stop taking it. This is especially significant in schizophrenia, where lack of insight into illness can already reduce adherence. There are also ethical concerns if powerful antipsychotics are used mainly to control behavior rather than to benefit the patient. Because of this, drug therapy should be monitored carefully, with attention to both symptom reduction and quality of life.
Practice Questions
Outline one way atypical antipsychotics differ from typical antipsychotics. (2 marks)
1 mark for identifying a valid difference, such as atypical drugs act on serotonin as well as dopamine, whereas typical drugs mainly block dopamine.
1 additional mark for clear development of that difference, such as noting that atypical drugs generally have fewer severe movement-related side effects or may help a broader range of symptoms.
Discuss drug therapy for schizophrenia, including typical and atypical antipsychotics. (6 marks)
Up to 4 marks for accurate knowledge and understanding:
Typical antipsychotics such as chlorpromazine mainly block dopamine receptors.
They are mainly used to reduce positive symptoms such as hallucinations and delusions.
Atypical antipsychotics such as clozapine and risperidone act on dopamine and serotonin.
Atypical drugs were developed to reduce severe movement side effects and may help a wider range of symptoms.
Up to 2 marks for evaluation:
Antipsychotic drugs are generally more effective than placebo.
Clozapine is often especially useful when other drugs have failed.
Side effects such as tardive dyskinesia, weight gain, sedation, or blood-monitoring demands may reduce compliance.
Typical and atypical drugs do not work equally well for every patient.
FAQ
Dopamine receptors may be blocked soon after a dose is taken, but clear clinical improvement often depends on slower changes in brain activity and behavior.
In practice, agitation or sleep problems may improve earlier, while hallucinations and delusions can take longer to reduce. This is why response is usually judged over weeks, not hours.
Akathisia is a side effect that creates a strong inner feeling of restlessness. A person may pace, fidget, or say they cannot sit still.
It can look like anxiety, agitation, or even worsening psychosis. That matters because the problem may be the medication itself, so increasing the dose could make the restlessness worse.
Chemicals in cigarette smoke can speed up liver enzymes that break down clozapine. This can lower the amount of the drug in the bloodstream.
If a person suddenly stops smoking, clozapine levels can rise, increasing the risk of side effects. This is why smoking changes should be reported during treatment and doses may need review.
Stopping suddenly can lead to a rapid return of symptoms, sometimes called rebound or relapse. Sleep disruption, anxiety, nausea, and general instability can also occur.
For some patients, the biggest risk is that they stop medication when feeling better, then become unwell again before support is in place. Dose changes are usually safer when supervised gradually.
It means using enough medication to control symptoms while keeping side effects as low as possible.
In practice, clinicians may start with a cautious dose, monitor response, and adjust slowly. The “best” dose varies between patients because sensitivity, age, physical health, smoking, and other medications can all affect how strongly a drug acts.
