Schizophrenia Flashcards
(Diagnosis and classification)
2 psychologists diagnosed 100 patients using DSM and ICD criteria
- Inter-rater reliability is poor
Psychologist 1 - 26 for DSM, 44 for ICD
Psychologist 2 - 13 for DSM, 24 for ICD - Criterion validity must also be poor
Schizophrenia is either under-diagnosed under the DSM or over-diagnosed under the ICD
Cheniaux
(Diagnosis and classification)
Co-morbidity
Depression - 50%
Substance abuse - 47%
PTSD - 29%
OCD - 23%
Poses question as to whether schizophrenia is a genuine disorder, or a severe manifestation of another
Buckley
(Classification and diagnosis)
- Men have been more likely to be diagnosed with schizophrenia since the 1980’s
- May be due to beta bias in research
- Female patients may be more able to function, maintaining jobs, families and relationships
Longenecker
(Biological explanations)
Large-scale family study - probability of sharing schizophrenia
General population - 1% Parents - 6% Siblings - 9% Children - 13% Fraternal twins - 17% Identical twins - 48%
There is a correlation between gentic similarity and schizophrenia
Gottesman
(Biological explanations)
Comparison of genome-wide studies
- Found 108 different genetic variations were associated with increased risk of schizophrenia
- These included those responsible for neurotransmitters like dopamine
There is no ‘schizogene’
Ripke
(Biological explanations)
Hypodopaminergia in the cortex
- Identified low levels of serotonin in the prefrontal cortex
- Prefrontal cortex - responsible for thinking and decision-making
- Linked this to negative symptoms
Goldman-Rakic
Prefrontal cortex - dopamine hypothesis
(Biological explanations)
Neural correlates of negative symptoms
- Found lower levels of activity in the ventral striatum than in controls
- Also observed a negative correlation between activity in the ventral striatum and severity of negative symptoms
Juckel
Ventral striatum - neural correlates
(Biological explanations)
Neural correlates of positive symptoms
Task: identify recorded speech as yourself or somebody else
- Brain scans of patients experiencing auditory hallucinations and a control group
- Lower activation levels observed in superior temporal gyrus and anterior cingulate gyrus in patients
- Patients also made more errors
Allen
(Biological explanations A03)
(Interactionist approach A03)
Support for genetic explanation: adoption studies
- Followed up 19,000 children adoptive from schizophrenic Finnish mothers
- Compared with control group of adoptees without genetic vulnerability
- Strict parenting characterised by criticism was implicated in the development of schizophrenia - but only for the genetically vulnerable group
Both genetics and environment involved in onset
Children of schizophrenia patients are still at heightened risk when adopted into families without history of schizophrenia
Tienari
(Biological explanations AO3)
Support for dopamine hypothesis: drugs
- Dopamine agonists like amphetamine (that increase dopamine levels) increase symptoms in sufferers and induce symptoms in non-sufferers
- Also, antipsychotic drugs work by reducing levels
Curran
(Biological explanations A03)
Focus is being diverted from the role of dopamine to the role of glutamate, another neurotransmitter
Moghaddam and Javitt
(Psychological explanations)
The Schizophrenogenic mother
Based on patients’ accounts of childhood - many spoke of a particular type of parents
- She is cold, rejecting, controlling
- Her attitudes tend to cause a family atmosphere of tension and secrecy
- This leads to distrust, which develops into paranoid delusions, and ultimately, schizophrenia
Fromm-Reichmann
(Psychological explanations)
Double-blind theory
- Child often in situations where they fear doing the wrong thing, but receive conflicting messages about what that is
They also feel unable to comment about things that they deem unfair or ask questions - When they ‘get it wrong’ they are punished by withdrawal of love
- They are left with the belief that the world is confusing and dangerous
- This leads to symptons like delusions and disorganised thinking
This is a risk-factor for schizophrenia
Bateson
(Psychological explanations)
Cognitive deficits
Two kinds of dysfunctional thought processing
- Metarepresentation - Ability to reflect on thoughts, behaviour, intentions and goals, as well as the actions of others.
Dysfunction in this can disrupts our ability to recognise thoughts and behaviour as our own. May explain
hallucinations and delusions of external control - Central control - Ability to suppress automatic responses
May explain disorganised speech
Frith
(Psychological explanations)
Cognitive deficits
Perceptual - Facial recognition
Set A: Configurational set (eyes further apart)
Set B: Featural set (different eyes)
Set C: Control set (chairs)
- Schizophrenics struggled the most with the configurational set
- This may lead to poor social interactional skills as they are less able to recognise facial expressions and respond appropriately (raised eyebrows)
Shin
(Psychological explanations A03)
Support for cognitive deficits
- Tested 30 patients against control group on cognitive tests
- Used the stroop test (naming the colour a word is written in rather than reading the word)
- Patients took twice as long to identify the colour
Stirling
The stroop test
(Psychological explanations A03)
Cognitive defecits pre-date schizophrenia onset
- 75% of patients experience problems with memory, attention, motor skills, executive functioning (controlling thoughts) prior to the onset of the illness
- Cognitive defecits are not a result of medication
O’Carroll
(Biological therapies)
Support for atypical psychotics - Clozapine
- Clozapine is more effective than typical antipsychotics
- It is effective in 30-50% of treatment-resistant cases
Meltzer
(Biological therapies)
Placebo effect
Meta-analysis of 100 studies comparing antipsychotics to placebos
- 70% improve on antipsychotics
- 25% improve on placebos
Approximately 45% genuine improvement
Davis
(Biological therapies)
Side effects
74% of patients discontinued their treatment within 18 months due to intolerable side effects
Typical drugs - Muscular disorders (Tardive dyskenesia)
Atypical drugs - Weight gain, metabolic effects
Any short-term effects are counteracted by physical side effects
Lieberman
(Biological therapies)
Relapse rates
Typical antipsychotics - 55%
Atypical antipsychotics - 42%
Atypical antipsychotics have less severe side effects, and a lower relapse rate
Schooler
(Psychological treatments A03)
Support for family therapy
- Found evidence that family therapy reduces hospital readmissions within a year
- Insufficient evidence, relapses may occur in the long-term
Pharoah
(Psychological treatments A03)
Family therapy works best in combination with drug treatments
63 patients
Group 1 - Drug treatment
Group 2 - Drug treatment with family therapy
Relapses
Group 1 - 61%
Group 2 - 33%
Xiang
(Psychological therapies)
Support for CBT
Reviewed 20 CBT trials
- Persistent evidence of reduced symptoms (especially positive ones)
- Lower relapse rates
- Speedier recovery for acutely ill patients
Successful in the short-term
Tarrier
(Psychological therapies A03)
Criticism of CBT
Meta-analysis of 50 studies of CBT over last 20 years
- Small therapeutic effect in reducing symptoms (even positive ones remained)
- Effect eliminated when using ‘blind testing’, when researchers do not know which patients have taken the drug
More thorough research suggests there may be no benefits
No evidence for long-term benefits
Jauhar
(Psychological therapies A03)
Support for token economy systems
Female patients with an average of 16 years institutionalisation
- Tokens given for chores to exchange for a film, visiting the canteen
- Given for completing chores - Brushing hair, making beds
- Number of daily chores rose from 5 to 42
TES can make patients more productive to counteract negative symptoms, particularly avolition
Allyon and Azrin
(Psychological therapies A03)
Criticism of token economy systems
Patients engage well in TES in immediate institutional care, but struggle to maintain jobs where they are paid on a long-term basis
Immediate reinforcement is most effective in encouraging patients to perform tasks
Also, employers should consider the needs of employees that suffer from schizophrenia to prevent relapse
Silverstein
(The interactionist approach)
The diathesis-stress model
- Diathesis (vulnerability) based on one ‘schizogene’
- Leads to the development of a ‘schizotypic personality’, one characteristic of which is sensitivity to stress
- Combination of the gene and stress in childhood (schizophrenogenic mother) may lead to the condition
Meehl
(Interactionist approach)
Modern understanding of diathesis - Trauma, as well as just genes, can cause diathesis
Neurodevelopmental model
- Early trauma alters the developing brain (e.g. child abuse)
- E.g. The hypothalmic-pituitary-adrenal sytem can become over-active, making people more vulnerable to stress
Read
(Interactionist approach)
Modern understanding of stress - cannabis
- Stressors can be anything that risks triggering schizophrenia
- This may be cannabis, as it is said to increase the risks by 7 times
- This may be due to interference with dopamine levels
Houston
(Interactionist approach)
Treatment
Should tackle biological and psychological aspects (drug therapy combined with psychological treatment)
Turkington
(Interactionist approach A03)
Treatment
Over 300 patients randomly allocated to one of 3 groups
- Medication + CBT
- Medication + standard counselling
- Medication only (control group)
- Patients in 1 and 2 had reduced symptoms compared to the medication only group
- However, there were no differences in hospital readmissions
Tarrier
