The genetic explanation

Question 1

What are the three genetic explanations?

Answer 1

Family, twin and adoption studies

Question 2

What does the genetic explanation believe?

Answer 2

The closer the biological relationship, the increased risk of schizophrenia developing

Question 3

Why are family twin and adoption studies used?

Answer 3

Establish how strong a genetic link is

Question 4

What did the family study by kety et al find?

Answer 4

207 high risk children, mothers had schizophrenia- 16.2% diagnosed
104 low risk children, health mothers- 1.9% diagnosed

Question 5

What did the family study by kendler et al find?

Answer 5

1st degree relatives of those with schizophrenia are 18 times more at risk (genetic link, risk increases with closer genetic relationship)

Question 6

What did the family study by gottesmean find?

Answer 6

48% risk in identical
17% risk in fraternal

Question 7

What is a criticism of family studies?

Answer 7

63% diagnosed have no family history, suggests other factors might be involved

Question 8

What did the twin study by Gottesman and Shields find?

Answer 8

Concordance of 42% for identical and 9% for fraternal

Question 9

What did the twin study by Torey find?

Answer 9

Reassessed 8 studies, concordance 26% for identical, 9% for fraternal

Question 10

What did the twin study by cardno et al find

Answer 10

Concordance of 40% for identical and 5.3% for fraternal

Question 11

What did the adoption study by Heston find?

Answer 11

47 children with schizophrenic mothers dopted at 1 month, 10 developed, non of the control developed

Question 12

What did the adoption study by tiener et al find?

Answer 12

112 adopted biological mum diagnosed, 135 adopted biological mum not diagnosed, 7% of 112 developed, 1.5% of 135 developed

Question 13

Evaluation of twin?

Answer 13

The genetic relatedness of identical would lead to high concordance rate should be similar but they arent. Suggests other factors involved