Adoption Study - Kety (1968) Flashcards
1
Q
Aim
A
- to find out if there is a genetic basis for schizophrenia as researcher compares the adoptive family and biological family of index participant (schizophrenic)
- to see if there is a higher rate of schizophrenia related illness among biological relatives than adoptive ones
2
Q
IV
A
- independent groups design
- has a control group with no history of mental illness
- natural experiment as adoption and schizophrenia are naturally occurring variables
3
Q
DV
A
researchers measured the prevalence of schizophrenia related illness among family members
4
Q
sample
A
- 34 schizophrenic patients with two MZ twins
- taken from the Danish Adoption Register for Copenhagen (DARC)
- aged 20-43
- were taken from a larger sample of 503 adoptees who had been admitted to a psychiatric hospital for general mental illness (opportunity sample)
- 33 mentally healthy controls were selected from DARC
- controls were matched to schizophrenic patients based on age gender and class
- 16 patients with chronic schizophrenic
- 7 patients with acute (short term) schizophrenia
- 11 with borderline schizophrenia
5
Q
procedure
A
- Kety located adoptive and biological relatives and used mental health register to access their mental states
- a panel of 4 pyschiatrists used the medical records to diagnose family members but it was a blind test so psychiatrists didn’t know if were biological or adoptive relatives
- after diagnosis they were assigned to adoptive groups (IA AND CA) or to biological groups (IB OR CB)
- psychiatrists diagnosed family members in these categories: B1-3 = just like index participant, D1= uncertain chronic schizophrenia, D2= uncertain acute schizophrenia, D3= uncertain borderline, C= schizoid or inadequate personality
- couldn’t find a conclusion for 4 people so they dropped them from study
6
Q
results
A
- Kety grouped together all relatives in B1-3, D1-3 and C categories as schizophrenic spectrum disorders
- more signs of schizophrenia spectrum disorders in the index participants biological family than adoptive
- more spectrum disorders in index participants biological family than in controls biological family
7
Q
conclusions
A
- there is a generic component to schizophrenia as adoptees were more likely to have schizophrenia in their biological family than adoptive
8
Q
generalisability
A
- large sample and covers ranges from teens to men and women in 40s therefore can be generalisable to Danes
- Danes are most white therefore ethnocentric
9
Q
reliability
A
- very reliable standardise procedures and replicated in other years which found similar findings the rider test retest reliability
- 4 psychiatrists had to agree on each diagnoses therefore interested reliability
- diagnostic categories were vague (inadequate personality?) and depended on subjective interpretation therefore unreliable
10
Q
application
A
if families are aware that their child has a genetic link to schizophrenia they can guide them away from drugs and stressful careers and watch out for early symptoms as schizophrenia is less destructive if diagnosed earlier
11
Q
validity
A
- ties with Rosenthal’s theory of diathesis stress model of schizophrenia (a genetic predisposition to schizophrenia still requires a trigger) giving study construct validity
- ties with Gottesmann and Shields (1966) research giving it concurrent validity
- vague and unclear concepts therefore subjectives making it invalid
- researchers didn’t consider environmental or personal history making it reductionist
- Joseph (2004) suggested that Kety changed the design to get the results they wanted therefore results are invalid as they don’t measure what they claim to measure
12
Q
ethics
A
- participants were directly approached no informed consent
- data was analysed under Danish laws without consent
- if Kety manipulated results then it questions scientific integrity and social responsibility
- if Kety created the false impression that schizophrenia is genetic it can cause stress anxiety and prejudice for families with schizophrenia history
