OxfordAQA International A-level Psychology (9685): 3.3.2 Schizophrenia – Revision Notes

For full explanations, evaluation and worked paragraphs, read the Schizophrenia study guide first. These notes condense it for revision.

They cover section 3.3.2 Schizophrenia in the OxfordAQA International AS and A-level Psychology (9685) specification, Version 3.1 (International A-level exams May/June 2020 onwards). The specification assesses this content in Section B of Unit 3: Advanced topics and research methods 2, a 1 hour 30 minute written exam of 90 marks, with 30 marks for Schizophrenia. Unit 3 is 30% of the International A-level.

Test yourself with the schizophrenia practice questions. The 9685 course hub and 9685 checklist show the rest of the course.

What the specification lists

• Symptoms: positive (hallucinations, delusions); negative (speech poverty, avolition).
• Reliability and validity in diagnosis: culture and gender bias, co-morbidity, symptom overlap.
• Biological explanations: genetics; neural correlates, including the dopamine hypothesis.
• Cognitive explanations: dysfunctional thought processing.
• Therapies: typical and atypical anti-psychotic drugs; cognitive therapy.

Key terms

Term	Definition
Positive symptom	An experience added to normal experience, e.g. hallucinations, delusions
Negative symptom	A normal ability reduced or lost, e.g. speech poverty, avolition
Hallucination	A perception with no external stimulus, most often hearing voices
Delusion	A firmly held false belief that resists contrary evidence (persecution, grandeur, control)
Speech poverty (alogia)	Reduced amount or content of speech; brief, empty replies
Avolition	Severe loss of motivation to start and sustain goal-directed activity
Reliability	Consistency of diagnosis between clinicians (inter-rater) or over time (test-retest)
Validity	Accuracy: whether the diagnosis identifies a real, distinct condition
Co-morbidity	Two or more disorders present in the same person at once
Symptom overlap	Symptoms shared by different disorders, blurring boundaries
Concordance	Percentage of twin pairs where both have the disorder
Diathesis-stress	Genetic vulnerability plus environmental trigger
Hyperdopaminergia	Excess dopamine activity, linked to positive symptoms
Hypodopaminergia	Too little dopamine activity, linked to negative symptoms
Metarepresentation	Ability to reflect on mental states, your own and others’ (Frith)
Willed action	Starting and controlling deliberate, self-generated behaviour such as speech (Frith)
Typical anti-psychotic	First-generation D2 antagonist, e.g. chlorpromazine
Atypical anti-psychotic	Second-generation drug acting on dopamine and serotonin, e.g. clozapine; generally fewer movement side effects
Tardive dyskinesia	Involuntary movements, a side effect mainly of typical drugs
Agranulocytosis	Dangerous fall in white blood cells, a risk with clozapine

Studies at a glance

Who	What	Finding	One evaluation point
Rosenhan (1973)	Healthy pseudopatients sought admission to 12 US hospitals	Almost all admitted with schizophrenia; stays 7-52 days	Later evidence casts serious doubt on how it was run (Scull, 2023)
Cheniaux et al. (2009)	Two psychiatrists assessed 100 inpatients with DSM-IV and ICD-10	Schizophrenia diagnosed more often under ICD-10	Shows the manual affects who is diagnosed: a validity issue
Loring and Powell (1988)	290 psychiatrists rated case studies varying only client sex and race	Sex and race of client and psychiatrist affected diagnosis	Vignettes lack the realism of real assessment
Luhrmann et al. (2015)	Interviews with 20 voice-hearers each in USA, India, Ghana	Violent commands reported more in USA; rich relationships with voices more in India and Ghana	Small samples per country
Cotton et al. (2009)	Records of 661 first-episode psychosis patients	Males had more severe symptoms and lower functioning	Record audit; cannot show why the difference exists
Buckley et al. (2009)	Review of comorbidities	About 50% comorbid depression; about 47% lifetime substance abuse	Raises the question of whether schizophrenia is one disorder
Hilker et al. (2018)	Danish registers, 31,524 twin pairs	Concordance 33% MZ, 7% DZ; heritability 79%	MZ concordance far below 100%, so environment matters
Tienari et al. (2004)	Adopted-away children of mothers with schizophrenia-spectrum disorders	Poor adoptive family functioning predicted disorder only in high-risk adoptees	Supports diathesis-stress
Ripke et al. (2014)	Genome-wide study, up to 36,989 cases	108 loci, including DRD2 and glutamate genes	Each gene has a small effect: polygenic
Davis et al. (1991)	Review of dopamine evidence	Low prefrontal and high mesolimbic dopamine	Explains both symptom types
Juckel et al. (2006)	fMRI, 10 unmedicated men and 10 controls	Reduced ventral striatum activity to reward cues, linked to negative symptoms	Very small sample
Allen et al. (2007)	fMRI while judging own or others’ recorded speech	Hallucinators misattributed own speech; altered temporal and anterior cingulate activity	Links biology with Frith’s self-monitoring idea
Frith and Done (1989)	23 drug-free acute patients on an error-prone motor task	Those with alien control experiences corrected fewer errors without visual feedback	Supports faulty central monitoring
Stirling et al. (2006)	30 patients, 18 controls	More thought disorder linked to poorer executive and semantic performance	Correlational: deficits may be effects
Kane et al. (1988)	268 treatment-resistant patients, clozapine vs chlorpromazine	30% responded to clozapine vs 4%	Clozapine needs blood monitoring
Adams et al. (2014)	Cochrane review of chlorpromazine vs placebo	Chlorpromazine reduced relapse	Evidence rated very low quality
Jauhar et al. (2014)	Meta-analysis of CBT trials	Small effect overall; very small on negative symptoms	Effects shrank with masked assessors

Must-know distinctions

• Hallucination vs delusion. A hallucination is a false perception; a delusion is a false belief.
• Speech poverty vs disorganised speech. Poverty is too little; disorganised speech is jumbled.
• Reliability vs validity. Agreement vs accuracy. Reliability is needed for validity but does not guarantee it.
• Co-morbidity vs symptom overlap. Two disorders in one person vs shared symptoms between disorders.
• Culture bias vs gender bias. Distortion by cultural norms vs distortion by gender.
• Original vs revised dopamine hypothesis. Excess dopamine only vs low prefrontal plus high mesolimbic.
• Self-monitoring vs willed action. Recognising your thoughts and actions as your own vs starting deliberate behaviour yourself.
• Typical vs atypical drugs. D2 blockers mainly for positive symptoms vs broader action, generally with fewer movement side effects.

Mini essay plan

Typical question: “Discuss biological explanations for schizophrenia.” (extended response)

1. Genetics (AO1). Family risk rises with relatedness. Hilker et al. (2018): MZ 33%, DZ 7%. Ripke et al. (2014): 108 loci; polygenic.
2. Neural correlates and dopamine (AO1). Original hypothesis: excess subcortical dopamine and D2 receptors. Revised (Davis et al., 1991). Juckel et al. (2006) on ventral striatum and negative symptoms.
3. Evaluation of genetics (AO3). MZ concordance far below 100%. Tienari et al. (2004) shows environment matters, so diathesis-stress fits better. Shared environment in twin studies.
4. Evaluation of dopamine (AO3). Drug evidence supports it, but this risks the treatment aetiology fallacy. Glutamate involvement. Small fMRI samples.
5. Comparison (AO3). Cognitive explanations (Frith) explain specific symptoms; the two can combine.
6. Judgement. Biology clearly contributes, but on its own it is reductionist.

Quick self-test

1. Define avolition.
2. Give one positive and one negative symptom named in the specification.
3. What is the difference between reliability and validity in diagnosis?
4. What did Cheniaux et al. (2009) find about ICD-10 and DSM-IV?
5. What is co-morbidity, and what figure did Buckley et al. (2009) give for depression?
6. What were the MZ and DZ concordance rates in Hilker et al. (2018)?
7. What did Tienari et al. (2004) show about adoptive families?
8. How did Davis et al. (1991) revise the dopamine hypothesis?
9. Which brain area did Juckel et al. (2006) link to negative symptoms?
10. In Frith’s model, which faulty process explains hearing voices?
11. Name one typical and one atypical anti-psychotic.
12. What did Jauhar et al. (2014) conclude about cognitive therapy?

Answers

1. A severe loss of motivation to start and keep up goal-directed activity.
2. Positive: hallucinations or delusions. Negative: speech poverty or avolition.
3. Reliability is consistency between clinicians or over time; validity is whether the diagnosis is accurate.
4. Schizophrenia was diagnosed more often under ICD-10 than DSM-IV.
5. Two or more disorders in one person at the same time; about 50% have comorbid depression.
6. 33% MZ and 7% DZ.
7. Poor adoptive-family functioning predicted schizophrenia-spectrum disorder only in adoptees at high genetic risk.
8. Low prefrontal dopamine (negative symptoms) alongside high mesolimbic dopamine (positive symptoms).
9. The ventral striatum.
10. Faulty self-monitoring (a metarepresentation problem), so inner speech is experienced as external.
11. Typical: chlorpromazine or haloperidol. Atypical: clozapine, risperidone or olanzapine.
12. CBT has a small effect on symptoms, and the effect shrinks when assessors are masked.

Where marks are usually lost

• Calling a hallucination a false belief, or a delusion a false perception.
• Listing symptoms without an example of how each shows in behaviour.
• Discussing “reliability” in an answer that asks about validity, or the reverse.
• Mentioning culture bias with no example or evidence.
• Giving twin concordance as proof of a purely genetic cause.
• Describing dopamine “imbalance” with no receptor type, brain area or direction.
• Explaining Frith’s model without linking each process to a named symptom.
• Treating typical and atypical drugs as identical in action and side effects.
• Evaluating therapies only by side effects, with no evidence on effectiveness.
• Using stigmatising language such as “schizophrenics”.

For deeper explanations and worked paragraphs, return to the Schizophrenia study guide. Reliability and validity as methods ideas are in Research methods 2. For whole-course strategy, see the 9685 exam preparation guide.

Official syllabus

OxfordAQA International AS and A-level Psychology (9685) specification, Version 3.1 (International A-level exams May/June 2020 onwards), section 3.3.2 Schizophrenia; Unit 3 details in section 2.3.