Discuss one or more biological explanations for schizophrenia mark scheme
If you’re preparing for AQA Psychology and come across the question “Discuss one or more biological explanations for schizophrenia”, don’t panic. This is a 16-mark essay that regularly appears on Paper 3, and knowing how to interpret the mark scheme can help you maximise your marks. In this post, we’ll break down how to use the ‘discuss one or more biological explanations for schizophrenia mark scheme’ to structure your essay, especially focusing on how to write four strong AO3 evaluation paragraphs.
Understanding the Mark Scheme
According to the AQA mark scheme, this essay is worth:
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AO1 (6 marks) for accurate knowledge of one or more biological explanations
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AO3 (10 marks) for discussion and evaluation
To achieve a Level 4 (13–16 marks), your essay needs clear, detailed knowledge and four well-developed evaluation points, using appropriate psychological terminology and structured argument.
AO1: What You Need to Include
Your AO1 should cover at least one biological explanation, but ideally two. Focus on:
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The dopamine hypothesis – including both hyperdopaminergia in the subcortex and hypodopaminergia in the prefrontal cortex.
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Genetic explanations – use evidence from twin and adoption studies and mention terms like polygenic and candidate genes.
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You can also reference other neural correlates (e.g., enlarged ventricles) and the role of other neurotransmitters like glutamate or serotonin.
Keep this section focused—6 marks means about 6 clear, accurate sentences.
AO3 Paragraph 1: Supporting Evidence
Start your evaluation by using relevant research. Leucht et al. (2012) found antipsychotic drugs targeting dopamine receptors to be more effective than placebos in reducing symptoms. This supports the dopamine hypothesis and strengthens the biological explanation. However, not all patients respond to these drugs, and atypical antipsychotics often affect serotonin as well—suggesting dopamine may not be the only factor involved.
AO3 Paragraph 2: Cause and Effect
A common criticism is that biological explanations often confuse correlation with causation. For example, changes in dopamine levels might be the result of schizophrenia, rather than the cause. Similarly, abnormal brain structures could be caused by the disorder itself or even long-term medication use. This weakens the internal validity of biological theories, as it’s hard to establish clear causal relationships.
AO3 Paragraph 3: Biological Reductionism
Biological explanations are often criticised for being reductionist. By focusing solely on genes or neurotransmitters, they ignore important psychological and social factors. This simplification may lead to treatments that focus only on medication, neglecting holistic approaches such as cognitive behavioural therapy or family intervention. A more balanced view, such as the diathesis-stress model, might be more appropriate.
AO3 Paragraph 4: Practical Applications
Despite the criticisms, one strength of biological explanations is their real-world application. Understanding the role of dopamine and genetics has led to the development of effective antipsychotic drugs. These treatments can reduce symptoms and improve quality of life for many individuals. However, the focus on medication can lead to a ‘quick fix’ mentality, which may not address the underlying causes or social impact of the disorder.
Final Thoughts
To score highly in this essay, use the mark scheme as a guide. Write a strong AO1 section covering at least one biological explanation, and then include four clear AO3 evaluation paragraphs, each with a point, supporting evidence or reasoning, and a counterpoint or consideration. Stick to psychological terminology and stay focused—this is the key to hitting Level 4.