Viral Explanations

Question 0

Torrey 88

Answer 0

Believes not a statistical quirk and risk of virus can be damaging especially during second trimester.
Influenza A seems most likely.
Hypothesised that infection enters brain and gestates until it is activated by hormonal changes during puberty.
Genetic predisposition required but MZ twins don’t have 100% concordance.
Supported by peaks in schizo throughout history coinciding with major flu epidemics.

Question 1

Viral Explanations

Answer 1

Believed seeds of disorder are down during the foetal development.
Possible certain nerve cells migrate to the wrong area and become miswired.
Possibly caused by mother catching a virus during pregnancy.
Child born during winter in northern hemisphere has a 10% higher risk than average.

Question 2

McGrath et al 03

Answer 2

Increased likelihood of schizo in babies born to Afro Caribbean immigrants in the UK.
Four times higher than genpop.
Vitamin D deficiency in pregnancy causes structural brain abnormalities in the foetus. Afro Caribbean’s have darker skin and require more sunlight than the UK gives.

Question 3

Vitamin D Deficiency

Answer 3

Rats deprived of vitamin D have babies with enlarged ventricles. Also show genetic defects as a result of the deficiency.