Lecture 4 Flashcards
What are positive symptoms of psychosis
Enhancement of normal behaviour→ abnormal perceptions) ideas,and thought disorder → thought -insertion withdrawal and poverty of speech content.
What are negative symptoms of psychosis
Attenuation of normal behaviour → emotional flattering motor and kohanioral disorder → abnormal post ur, catatonia
What evidence is there of genetics affecting schizophrenia
Parents and siblings 10x more likely to develop the disorder
Children I5X
Not 100% genetic
Environmental factors affecting schizophrenia
Prenatal exposure to virus → high increancein people born after major flu epidemics
Delivery complications → forceps leads to greater disease risk
Social factors → upbringing
What structural abnormalities one seen in s hichephrenen
No signature abnormatitefound but the is reduced temporal lobe volume and enlarged ventricles → not seen all no change in glia so probably not degenerative reduced activity in frontal cortex
What evidence his there for the dopamine theory for schizophrenia, what can it not explain
Amphetamine causes very similar symptoms to positive symptoms
Dopamine agonists used to treat
But negative symptoms not caused by amphetamines nor treated by antagonist, also changes in dopan one May be caused by long term treatment
What evidence is there for the sertonin theory
LSD causes calluinations c5-ht agnoist
What evidence is there for the glutamate theory
Antagonist of glutamate ( phencylidie) → causes similar changesto that seen in silo phone → both pos and neg →and cognitivealso excavates symptoms in sufferers
What changes seen inglutavate in schsophina
Reduced CST glutamate in schiophereic patients , reduced cordial glutamate post marten, increased guitamale receptors postmortem increased binding to literate reoplosin context basal ganglia form l - s on and hippocompal both increases and decreases in glutamate binding seen in the temporal lobe
Decreased glutamate uptake sites in the cingulate cortex inconsistent data s lot of ability due to possibly diagnosis criteria changes) are important but machismo unknown
What is the new developmental hypothesis of shicopheria
Abnormal neural selection and migration during foetal brain development → symptoms appear won normal restructuring durning adolences unmasks the problem night be contributed by regudecad NGF starvation ect
What’s the neurodegeneration hypothesis→ evidence
Progression is more consistent with neurodegeneration antiphycotic works with time so nerodgeration → perhaps excitotoxic or psychotic episodes are toxic to the brain early effective treatment May delay progression
A simple model
Genetic predisposition → environmental factors affect cortical development → deficit infunction or interconnections.
Negative symptoms → innaproval temporal frontal communication
Positive symptoms → innopropiate output from temporal lobe
