kety

Question 1

kety aim

Answer 1

To find out if there is a genetic basis for schizophrenia and to see if there is a higher rate of schizophrenia-related illness among biological relatives than adoptive relatives.

Question 2

kety iv and dv

Answer 2

IV: Schizophrenia sufferers and a Control Group with no history of mental illness.
DV: The researcher’s measured the prevalence of schizophrenia-related mental illness among family
members

Question 3

kety sample

Answer 3

34 schizophrenic patients (two of them MZ twins) taken from the Danish Adoption Register for Copenhagen. They were aged 20-43.
33 mentally-healthy Controls were selected from the Danish Adoption Registry. They were
matched to the schizophrenic patients on age, gender, the age at which they were adopted and the social class of the adoptive family.

Question 4

kety procedure

Answer 4

Kety used the Danish family records to locate adoptive and biological relatives of all the
participants.
* He tracked down 463 relatives and used the mental health register to assess their mental status.
* A panel of 4 Danish psychiatrists used the medical records to diagnose the family members. This was a “blind test” because the psychiatrists did not know whether the records were from an adoptive or a biological family member.
* Once the diagnoses had been made, the identities were revealed and they were assigned to adoptive family groups (IA and CA) or to the biological family groups (IB or CB).
* 4 Psychiatrists diagnosed the family based on their medical records and classified them as SZ or not.
* In 4 cases, they couldn’t reach a conclusion and these relatives were dropped from the study.

Question 5

kety results

Answer 5

• Kety et al. grouped together all the relatives in the B1-B3, D1-D3 and C categories as
  “schizophrenic spectrum disorders”.
• The research found more signs of schizophrenic spectrum disorders in the index participants’ biological family than their adoptive family
• They also found more spectrum disorders in the index participants’ biological families than in the Controls’ biological families.
• Of 150 biological relatives of index cases;
• 13 (8.7%) had a diagnosis of schizophrenia, uncertain schizophrenia, or inadequate
  personality
• Of 156 biological relatives of the controls;
• 3 (1.9%) had a diagnosis of schizophrenia, uncertain schizophrenia, or inadequate
  personality

Question 6

kety conclusions

Answer 6

There seems to be a genetic component to schizophrenia. Schizophrenic adoptees were more likely to have schizophrenia in their biological family than their adoptive family. Their biological families were more likely to have schizophrenia than the families of Controls.