Schizophrenia Flashcards
Positive symptoms of schizophrenia (2)
- Hallucinations (additional sensory experiences)
- Delusions (irrational beliefs of the world)
Negative symptoms of schizophrenia (2)
- Avolition (lack of purposeful, willed behaviour i.e personal hygiene)
- Speech poverty (lack of quality/quantity of speech)
Problems with classification/diagnosis of schizophrenia
- Cultural bias
- Comorbidity/symptom overlap
- Labelling/stereotyping
Loring and Powell (1988) - gender bias study
- 290 M/F psychiatrists given two patient reports
- If two patients describe as N/A or male, 56% diagnosis
- If described as female, 20% diagnosis
- Discrepancy not present for female psychiatrists
Buckly (2009) - comorbidity rates study
- 50% with depression
- 47% with drug abuse
- 23% with OCD
Barnes (2004) - cultural bias
- Found that African Americans were more likely to be diagnosed (hearing voices, hallucinations etc)
Gottesman (1991) - twin concordance study (3)
- 48% MZ
- 17% DZ
- Compared to 1% for general population
Tienari (2004) - adopted children of SZ mothers
- 5.8% diagnosis when adopted to healthy families
- 36.8% when adopted to dysfunctional families
Think about what causes negative and positive symptons
What is the revised dopamine hypothesis?
Negative symptoms - deficit of dopamine in prefrontal cortex
Postive symptoms - excess dopamine in prefrontal cortex
The orignal hypothesis only uses the excess dompamine receptors theory
What are neural correlates?
Variations in neural structure and biochemistry which are correlated with SZ
Johnstone (1976) - ventricles study
Those with larger than average ventricles had increased risk of SZ
What are the 3 biological explanations for schizophrenia?
- Genetic
- Dopamine hypothesis
- Neural correlates/brain structure
What is the double bind theory?
When a child receives mixed messages on the verbal and non-verbal levels, they develop an incoherent version of reality
What is the expressed emotions theory?
SZ is more likely when a patients family exhibits;
1. Exaggerated involvement
2. Criticism/hostility to individual
Butzlaff and Hooley (1998) - EE study
- Meta-analysis of 27 studies
- Relapse is significantly more likely with families which express EE
What is Frith’s cognitive theory of SZ? (3)
- Identified two types of dysfunctional thought processing
- Central control is faulty, unable to repress automatic urges
- Faults in meta-representation can create a feeling that ones actions are being controlled externally
Frith (1992) - SZ PET scans (3)
- 30 SZ patients
- Found reduced blood flow to the prefrontal cortex (avolition/suppression of urges)
- Increased activity in the temporal lobe (memory retrieval)
3 negative evaluations of the cognitive explanations for SZ
- Reductionist
- Lacks causal relationship
- Places blame on individual
What are the 3 psychological explanations for schizophrenia?
- Expressed emotion
- Double bind theory
- Frith’s cognitive theory
Typical antipsychotics (chlorpromazine)
- Bind to dopamine receptors and prevent firing (inhibitory)
- Long lasting effects
Atypical antipsychotics (clozapine)
- Bind to dopamine receptors and prevent firing (inhibitory)
- Rapidly disassociate to allow normal transmission
Leucht et al (2012) - placebo vs relapse
- Meta-analysis of 65 studies
- Placebo = 64% relapse in 12 months
- 27% relapse for antipsychotics
Side effects of typical antipsychotics (3)
- Tarkive dyskinesia
- Lethargy
- Dry mouth
Side effects of atypical antipsychotics (3)
- Agranulocytosis
- Weight gain
- Cardiovascular problems
Crossley et al (2010) - atypical vs typical antipsychotics
- Meta-analysis of 15 studies
- No difference in effect on symptoms
- Has different side effects however
Positive evaluations of drug therapies (2)
- Cheaper/better for economy
- Prevents institutionalisation, allows for patient autonomy
Psychological ways of treating SZ (3)
- CBTp
- Token economy
- Family therapy
How does CBTp work? (3)
- Encouraged to find root causes of symptoms
- Irrational thoughts challenged
- Via ABCDE framework
How does family therapy work? (3)
- Lower levels of EE
- Restructure family beliefs on SZ
- Lower relapse
NICE 2015 review - CBTp effectiveness
Found that compared with medication alone, rehospitalisation rates reduced after 18 months with CBTp
Haddock et al (2013) - CBTp availability
- 187 SZ patients
- Only 13 offered CBTp
Freeman et al (2013) - CBTp refusal
- Found significant number of patients refusing/failing to attend therapy
Lobban et al (2013) - family therapy effectiveness
- 50 family therapy studies
- Found 60% significant positive impact
How does token economy work for treating SZ? (3)
- Target behaviours identified
- Tokens rewarded for exhibiting these behaviours
- Able to exchange tokens for rewards
Dickerson et al (2005) - token economy effectiveness
- 13 studies of token economies
- 11 reported beneficial effects
Issues of the token economy (2)
- Ethical issues
- Do not treat symptoms of SZ
Which 2 studies support the interactionist approach?
- Gottesman (1991) - MZ twins only 48% concordance
- Tienari (2004) - 5.8% vs 36.8% of adopted children
Tarrier (1998) - interactionist approach support
- Drug vs drug + CBT conditions
- Patients in combined conditions had significant improvement in the severity/number of symptoms
2 negative evaluations of the interactionist approach (2)
- Mechanism which links stressor and biological response is not understood
- Certain birth complications can increase the risk of schizophrenia (Verdoux et al 1998)
What is the schizophrenogenic mother theory?
- Mother is cold, rejecting and controlling
- Creates family climate of tension and secrecy
- Leads to distrust and paranoid delusions
Stirling (2006) - Central control evaluation point
- 30 SZ and 18 controls given Stroop test
- SZ individuals took twice as long to name the ink colour
- Suggest faulty central control
Key studies for this topic (biological)
- Gottesman (1991) - twin concordance
- Tienari (2004) - adopted children of SZ mothers
- Johnstone (1976) - ventricles study
- Firth (1992) - SZ PET scans
Key studies for this topic (misc)
- Loring and Powell (1988) - gender bias
- Buckly (2009) - comorbidity
- Barnes (2004) - cultural bias
- Butzlaff and Hooley (1998) - EE study
