Drug Therapy for Schizophrenia (AQA A Level Psychology): Revision Note

Typical antipsychotics

• Antipsychotic drugs are used to treat a range of mental disorders, including schizophrenia (psychotic refers to any condition in which a person loses touch with reality)

• Typical antipsychotics are also known as first-generation antipsychotics, as they have been in use since the 1950s

• Typical antipsychotics are dopamine antagonists, i.e., they inhibit dopamine activity by blocking dopamine receptors in the synapse

• Examples of typical antipsychotics include

  • chlorpromazine,

  • trifluoperazine

  • acetophenazine

  • haloperidol 

• Typical antipsychotics are effective at treating the positive symptoms of schizophrenia, e.g. delusions

• Haloperidol and chlorpromazine come with side effects, some of which are quite severe, e.g., drowsiness, agitation, dry mouth, blurred vision, lack of emotional response, dizziness, muscle stiffness or spasms

• Over-use of typical antipsychotics may lead to tardive dyskinesia or neuroleptic malignant syndrome (a result of dopamine being blocked in the hypothalamus)

Atypical antipsychotics

• Atypical antipsychotics are second-generation antipsychotics, in use since the 1970s, developed to maintain or improve effectiveness while minimising the side effects of typical antipsychotics

• Atypical antipsychotics are dopamine antagonists, they inhibit dopamine activity by blocking dopamine receptors in the synapse, but they may act on serotonin receptors (and, in clozapine's case, glutamate receptors)

• Both the positive and negative symptoms of schizophrenia are treated with atypical antipsychotics

• Examples of atypical antipsychotics include

  • risperidone

  • olanzapine

  • brexpiprazole

  • clozapine

• Clozapine is prescribed when other antipsychotic drugs have not worked

  • Because of its potentially fatal side effect (agranulocytosis, a blood condition), people taking it must have regular blood tests

• Clozapine's action on serotonin receptors is believed to improve mood and reduce depression and anxiety

  • This is important as 30–50% of people with schizophrenia attempt suicide at some point

Research which investigates drug therapies

• Marder & Meibach (1994) - People with schizophrenia who took risperidone compared to haloperidol or a placebo showed significant improvement in both positive and negative symptoms 

• Geddes et al. (2000) conducted a review of research and found that there is no real difference in effectiveness between first- and second-generation antipsychotics

  • Typical antipsychotics should be prescribed in the early stages of an episode of schizophrenia unless the patient has previously had side-effects including disjointed movement or muscles spasms

Evaluation of drug therapies

Strengths

• There is a body of compelling research evidence which suggests that antipsychotics are an effective treatment for schizophrenia

• Antipsychotics are most effective at treating patients with the most severe symptoms who may not be treatable using non-drug therapies (Furukawa et al. 2015)

Limitations

• Patients with milder, less extreme forms of schizophrenia benefit less from taking antipsychotics and may additionally experience adverse side effects

• It is not clear how effective antipsychotics are in preventing relapses in patients who are in remission

Issues & Debates

• Drug therapies support a biological determinist view, as they assume schizophrenia symptoms are caused by neurochemical imbalances

  • This can undermine the patient’s sense of control over their condition and implies that behaviour is driven by biology, not personal choice or cognitive factors

• Drug therapies take a biologically reductionist approach, treating schizophrenia as purely a chemical imbalance

  • They overlook important psychological and social factors (e.g., cognitive dysfunction, family environment)

  • This limits the explanation’s holistic value and may reduce long-term treatment success if non-biological causes are left unaddressed