9990 · 1.1.2
Explanations of schizophrenia flashcards
Revision flashcards for Cambridge 9990 Explanations of schizophrenia (syllabus 1.1.2). Flip, recall, then mark a real past-paper question.
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Gottesman (1991) key finding?
MZ twin concordance ~48% vs DZ ~17% — strong genetic component but not 100%, so environment also matters.
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Dopamine hypothesis?
Schizophrenia linked to excess dopamine (especially D2) in mesolimbic pathway — positive symptoms; hypofrontality may explain negative symptoms.
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What is expressed emotion (EE)?
High criticism, hostility, or over-involvement from family — linked to relapse in schizophrenia (Brown et al.).
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Tienari et al. (2004)?
Adopted children with genetic risk for schizophrenia more likely to develop disorder if raised in dysfunctional families — gene–environment interaction.
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Diathesis-stress model?
Biological vulnerability (diathesis) plus environmental stressor (e.g. life events, EE) triggers onset — interactionist, not purely nature or nurture.
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Reductionism issue?
Biological accounts explain symptoms via genes/neurotransmitters but may ignore social context; psychological accounts may underplay brain mechanisms.
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What is the dopamine hypothesis of schizophrenia?
The theory that schizophrenia is caused by abnormal dopamine activity. The revised version suggests hyperdopaminergia (excess dopamine) in the subcortex causes positive symptoms, while hypodopaminergia (low dopamine) in the prefrontal cortex causes negative symptoms.
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Define 'Expressed Emotion' (EE).
A family communication style involving high levels of criticism, hostility, and emotional over-involvement directed at a person with schizophrenia. It is a strong predictor of relapse rather than a direct cause.
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What is 'metarepresentation' in the context of schizophrenia?
A cognitive concept for the ability to reflect on one's own thoughts and actions. Frith proposed that a failure in this process leads to positive symptoms like auditory hallucinations, as individuals cannot distinguish their inner speech from external voices.
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What were the key findings of Gottesman's (1991) large-scale family study?
He found a strong positive correlation between genetic similarity and the risk of developing schizophrenia. Concordance rates were 48% for MZ twins, 17% for DZ twins, and 9% for siblings, providing strong evidence for a genetic component.
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Name two neural correlates of schizophrenia.
1. Enlarged ventricles (fluid-filled cavities), which suggests brain tissue loss, particularly in central brain areas. 2. Reduced grey matter volume and lower activation levels in the temporal and frontal lobes, linked to various symptoms.
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What is a 'polygenic' explanation of schizophrenia?
It means that the disorder is not caused by a single gene, but by the combined effects of many different genes. Each gene confers a small increase in risk, and a certain combination is needed to pass the threshold of genetic vulnerability.
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What is a key piece of evidence supporting the role of Expressed Emotion (EE) in schizophrenia?
Kavanagh's (1992) review found that the mean relapse rate for patients returning to high-EE families was 48%, compared to only 21% for those returning to low-EE families. This shows EE is a significant risk factor for relapse.