heston - genetic contributions to schizophrenia

Question 1

aim

Answer 1

• test the genetic contributions to schizophrenia
• by comparing adults born to schizophrenic mothers who were separated from them shortly after birth
• with a control group of adopted children who didn’t have schizophrenia

Question 2

experimental group

Answer 2

• 47 adoptees whose
  biological mothers had been diagnosed with schizophrenia
• born in Oregon state hospital between 1915-1945
• separated from their mothers within 3 days and had no other contact with them

Question 3

control group

Answer 3

• 50 adoptees whose mothers had not been diagnosed with schizophrenia
• selected from sam’s foundling homes as experimental group
• matched for sex, type of placement and length of time in child care institutions
• mother of subjects were screened to ensure they weren’t known to have a mental illness history
• all control children went to families where both children were present

Question 4

procedure

Answer 4

• researchers assessed participants psychological adjustment using primary and secondary data

Question 5

secondary data used

Answer 5

school records
police records
veterans records
hospital records

Question 6

primary data source used

Answer 6

-personal interviews
-psychological testing
-minnesota multiphasic personality inventory test

Question 7

what does MMPI test

Answer 7

personality traits
psychopathology
used to diagnose mental health conditions

Question 8

how were the subjects case file evaluated

Answer 8

• blindly and independently by 2 psychiatrists

Question 9

what was the correlation coefficient between the ratings of the 2 psychiatrists

Answer 9

0.822 = high inter rater reliability

Question 10

results control group

Answer 10

• no cases of schizophrenia found
• no significant increase in other mental health disorders

Question 11

results experimental group

Answer 11

• 10% (5/47) participants had schizophrenia
• 50% showed psychosocial disability,e.g sociopathy, neurotic personality disorder and maladjustment
• other 50% were successful adults

Question 12

conclusion

Answer 12

• findings support a genetic component in schizophrenia as the incidence was significantly higher in children of schizophrenic mothers
• however not all adopted children of schizophrenic mothers developed schizophrenia so environmental factors may play a role

Question 13

generalizability

Answer 13

• only had sample from adopted individuals to schizophrenic mothers from oregon usa
• not representative to rest of world

Question 14

reliability

Answer 14

• standardized procedures involved
• researchers looked at police aid school reports for all participants
• there were lots of data correlations
• high correlation of 2 researchers = high inter rater reliability (0.822) so results are consistent

Question 15

application

Answer 15

• supplies evidence supporting genetic basis of schizophrenia which can inform genetic counseling and early intervention strategies for at risk individuals

Question 16

validity

Answer 16

• high ecological validity as participants were brought up with everyday life’s
• use of past and present records
• extraneous variables such as the parents the adoptee was brought up with may have had an environmental impact on their upbringing

Question 17

ethics

Answer 17

• protection from harm = patients may have gone under mental distress due to questions about their family history of schizophrenia