Schizophrenia Flashcards
(43 cards)
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
