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