Biological Explanations to Sz.
Genetic explanation.
Inheritance.
Family studies.
Twin studies.
Closer the relation, the greater chance of inheritance.
Parent/sibling link is 12%
If both parents have it, 40% likely child has it.
1% of general population has Sz.
Monozygotic twins have higher concordance rates than Dizygotic twins.
Shows some degree of heredity.
Specific Genes.
It is polygenic.
108 genes associated with development of Sz.
Dopamine hypothesis.
Dopamine is a NT, causes neurons to fire.
Sz believed to be caused by too much dopamine.
these fire too much, transmit too many messages.
Too many dopamine receptors, developed from genetics.
Original version of hypothesis.
Recent version of the hypothesis.
Too much in the subcortex (centre of the brain).
Too little in pre-frontal cortex = negative symptoms, responsible for thinking and decision making.
Too much in Broca's area = poverty of speech.
Neural correlates.
Structural and functional brain abnormalities.
fMRIs used to scan for abnormalities.
Enlarged ventricles.
Associated with damage to brain areas.
often associated with negative symptoms.
Sufferers had enlarged brain ventricles, normal people did not.