KETYS ADOPTION STUDY

• aim of study

  to establish if theres a genetic basis for schizophrenia by comparing the adoptive family and the biological family of a schizophrenia patients
• sample

  -34 schizophrenic patients from danish adoption register

  -aged 20-43

  -split into 3 groups( chronic sufferer, short-term sufferer or had borderline diagnosis )

  -33 healthy controls were matched to schizophrenic patients on gender, age at which were adopted & social class of the adoptive family

  uses amatched pairs design
• procedure

  - used danish family records, tracked down 463 relatives& used themental health register to assess their mental status

  -relatives diagnosed by psychiatrists who didn't know their relationship to the patient ( blind test )using their medical records. --- psychiatrists diagnosed family member into 3 categories

  1)just like the SZ patient( adoptive child )

  2)uncertain level of sz

  3)inadequate personality
• why was blind test helpful

  didnt know if they were diagnosing an adoptive or biological memberso avoids researcher bias of matching aims of their study
• results

  - found more signs of sz disorders in both adoptive child and their biological family rather than their adoptive family

  -more sz disorders found in the adoptive child biological family than in control biological families

  -Of 150 biological relatives 8.7% had a diagnosis of sz or inadequate personality compared to 1.9% in biological families of control sample
• conclusions

  -schizophrenia seems to have a genetic component as adoptees were more likely to have sz in their biological family than their adoptive family

  -adoptive sample was also more likely to have sz in their biological families than the control sample
• explain

  one improvementcould be made to studychange the medical records to 30 min unstructured interviewsasking on sz zymptoms toform qualitative datato allow formore in-depth analysis
• IV 1 and IV 2 AND DV

  in study is ?

  IV1 -type of family relative

  IV2 -SZ sufferer or not

  DV -prevalence of SZ disorder amongst family members
• strength -matched pairs

  matched pairs design ,one strength of the study is they used matched pairs design as 33 healthy controls were matched to sz ppts on gender, age and social class. allows kety to make comparisons to the control group on the diagnosis of sz in biological and adoptive relatives whilst controlling for individual differences
• weakness ofsample

  one weakness is the sample not representative of wider population as taken from a danish register.this is weakness as the study on comparing adoptive & biological relatives cant be generalised to all in society
• weakness ofmedical records

  weakness of medical records to diagnose relatives into 3 categories.this is a weakness because it reduces accuracy of diagnosis of relatives mental status therefore lowering validity of results on the genetic basis for sz
• Strength:Inter-rater Reliability

  strength is it had inter-rater reliability as there were 4 psychiatrists who were diagnosing relatives based on their medical records meant that there was consistency between opinions of researchers as they had to agree on the diagnosis of the relatives