heston - genetic contributions to schizophrenia Flashcards
aim
to 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
experimental group
-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
control group
- 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
procedure
- researchers assessed participants psychological adjustment using primary and secondary data
secondary data used
school records
police records
veterans records
hospital records
primary data source used
-personal interviews
-psychological testing
-minnesota multiphasic personality inventory test
what does MMPI test
personality traits
psychopathology
used to diagnose mental health conditions
how were the subjects case file evaluated
- blindly and independently by 2 psychiatrists
what was the correlation coefficient between the ratings of the 2 psychiatrists
0.822 = high inter rater reliability
results control group
- no cases of schizophrenia found
- no significant increase in other mental health disorders
results experimental group
- 10% (5/47) participants had schizophrenia
- 50% showed psychosocial disability,e.g sociopathy, neurotic personality disorder and maladjustment
- other 50% were successful adults
conclusion
-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
generalizability
- only had sample from adopted individuals to schizophrenic mothers from oregon usa
- not representative to rest of world
reliability
- 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
application
- supplies evidence supporting genetic basis of schizophrenia which can inform genetic counseling and early intervention strategies for at risk individuals
validity
- 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
ethics
- protection from harm = patients may have gone under mental distress due to questions about their family history of schizophrenia
