Schizophrenia Flashcards
Classification of Schizophrenia - ICD-11
Requires at least two negative symptoms for diagnosis.
Classification of Schizophrenia - DSM-5
Requires at least one positive symptom (e.g., delusions, hallucinations).
Benefits of Standardised Classification
Improves reliability.
Issue with Inter-Rater Reliability
Low inter-rater reliability (Cheniaux et al. – different psychiatrists gave different diagnoses).
Positive Symptoms of Schizophrenia
Excess/distorted function: Hallucinations, Delusions, Disorganised Speech, Catatonia.
Negative Symptoms of Schizophrenia
Loss of normal function: Avolition, Alogia, Flattened Affect.
Benefits of Identifying Symptoms
Helps identify & categorise symptoms.
Issue with Symptom Overlap
Symptom overlap with other disorders (e.g., bipolar disorder).
Genetic Basis of Schizophrenia - Twin Studies
MZ twins: 48% concordance; DZ twins: 17% concordance.
Polygenic & Aetiologically Heterogeneous
Many genes contribute (e.g., dopamine genes).
Support for Genetic Basis
Strong empirical support (higher risk in families).
Limitation of Genetic Studies
Not 100% concordance – must be environmental factors too.
The Dopamine Hypothesis - Hyperdopaminergia
Excess in subcortex → Positive symptoms (e.g., hallucinations).
The Dopamine Hypothesis - Hypodopaminergia
Deficit in prefrontal cortex → Negative symptoms.
Support for Dopamine Hypothesis
Drug support (amphetamines worsen symptoms, antipsychotics reduce symptoms).
Limitation of Dopamine Hypothesis
Glutamate may also play a role (not just dopamine).
Neural Correlates - Enlarged Ventricles
Less brain tissue, associated with negative symptoms.
Neural Correlates - Prefrontal Cortex
Low activity linked to poor decision-making.
Support for Neural Correlates
Brain scan evidence supports abnormalities.
Limitation of Neural Correlates
Cause or effect? Brain changes may be a result of schizophrenia, not a cause.
Family Dysfunction - Schizophrenogenic Mother
Cold, rejecting, controlling → Leads to paranoia.
Family Dysfunction - Double Bind Theory
Mixed messages → Confusion & withdrawal.
Family Dysfunction - Expressed Emotion (EE)
High criticism, hostility, emotional over-involvement → Relapse risk.
Support for Expressed Emotion
EE has empirical support (high EE families linked to relapse).
Limitation of Family Dysfunction Theory
Blames parents – ethical concerns.
Cognitive Explanations - Dysfunctional Thought Processing
Meta-representation Deficit and Central Control Deficit.
Support for Cognitive Explanations
Evidence (Stirling et al. – schizophrenia patients struggled with cognitive tasks).
Limitation of Cognitive Explanations
Cognitive issues may be a symptom, not a cause.
Typical Antipsychotics (e.g., Chlorpromazine)
Block dopamine receptors → Reduce positive symptoms.
Support for Typical Antipsychotics
Effective for many (Thornley et al. – better than placebo).
Limitation of Typical Antipsychotics
Serious side effects (e.g., tardive dyskinesia – involuntary movements).
Atypical Antipsychotics (e.g., Clozapine, Risperidone)
Targets dopamine, serotonin & glutamate → Works on positive & negative symptoms.
Support for Atypical Antipsychotics
Fewer side effects, effective for resistant cases.
Limitation of Atypical Antipsychotics
Clozapine risk – can cause agranulocytosis (fatal blood disorder).
Cognitive Behavioural Therapy (CBT)
Challenges irrational thoughts (e.g., ‘voices are controlling me’).
Support for CBT
Jauhar et al. – Modest reduction in symptoms.
Limitation of CBT
Doesn’t work for all (severe cases may not engage).
Family Therapy
Reduces EE, improves communication & support.
Support for Family Therapy
Pharaoh et al. – Reduced relapse rates.
Limitation of Family Therapy
Not a cure – only improves family dynamics.
Token Economies (Behavioural Therapy)
Operant conditioning – rewards for adaptive behaviour (e.g., hygiene, socialising).
Support for Token Economies
Improves daily functioning.
Limitation of Token Economies
Ethical issues – denies rewards to most severe patients.
The Diathesis-Stress Model
Diathesis (Genetic Vulnerability) + Stress (Trigger) → Schizophrenia.
Example of Diathesis-Stress Model
Tienari et al. – High-risk adoptees more likely to develop schizophrenia if adopted into dysfunctional families.
Treatment for Diathesis-Stress Model
Combination of drugs + CBT most effective.
Support for Diathesis-Stress Model
Best explanation – integrates biology & psychology.
Limitation of Diathesis-Stress Model
Difficult to measure exact interactions between factors.
