Kety et al (1968)

Question 1

What type of study is this?

Answer 1

ADOPTION!!

Question 2

What is the aim?

Answer 2

To find out if there’s a genetic basis for schizophrenia

Question 3

How many participants were there?

Answer 3

34

Question 4

Where were participants recruited from?

Answer 4

Danish adoption register

Question 5

How old were the participants?

Answer 5

20-43

Question 6

What were the categories the schizophrenics were split up into?

Answer 6

Chronic schizophrenia (16)
Acute schizophrenia (7)
Borderline schizophrenia (11)

Question 7

How many control ppts were there?

Answer 7

33

Question 8

What were the schizophrenics and controls matched on?

Answer 8

Age, Gender, Age adopted, Class

Question 9

Who did researchers track down?

Answer 9

Biological and adopted relatives of participants

Question 10

What type of test was used to diagnose family?

Answer 10

Blind test

Question 11

What were the conditions the relatives were assigned to after diagnosis?

Answer 11

Adoptive (IA, CA) or Biological groups (IB, CB)

Question 12

What’s an example of one of the diagnosis categories?

Answer 12

‘uncertain chronic schizophrenia’

Question 13

What were the results?

Answer 13

• More signs of schizophrenic spectrum disorders in index ppts biological family, rather than adopted family
• More spectrum disorder in index biological family than controls biological family

Question 14

What can we conclude from Kety’s study?

Answer 14

There’s a genetic basis for schizophrenia because schizophrenia adoptees more likely to have schizophrenia in biological family than adopted family

Question 15

How is generalisability increased?

Answer 15

Sample of men and women from a range of ages which is representative of target population

Question 16

How is generalisability decreased?

Answer 16

Hard to generalise to other ethnic groups as sample was homogenous and white

Question 17

How is reliability increased?

Answer 17

Inter-rater reliability as 4 psychiatrists were used to diagnose relatives (only 4 cases they couldn’t agree but removed)

Question 18

How is reliability decreased?

Answer 18

Schizophrenia categories were vague and dependent on subjective interpretation

Question 19

What are the applications of this study?

Answer 19

• If families are away the child has a genetic predisposition, they can steer the child away from environmental triggers e.g., drugs and look out for symptoms

Question 20

How is validity increased?

Answer 20

Construct validity from diathesis stress model

Question 21

How is validity descreased?

Answer 21

Joseph (2014) suggests that Kety changed design to get the results he was looking for so findings didn’t measure what they claimed to measure

Question 22

How does the study violate ethical guidelines?

Answer 22

• No informed consent as participants weren’t directly approached as data analysed under Danish laws
• Issues of social responsibility as they had a responsibility to find out whether there was a genetic component to help society
• Issues of protection from harm/ socially sensitive as Kety suggested that schizophrenia is genetically inheritable which may lead families with mental illness history to experience prejudice