Tienari et al. (2004)

Question 1

aim ?

Answer 1

to investigate whether there was a genetic explanation of schizophrenia

Question 2

what type of study was this ?

Answer 2

adoption study

Question 3

what did the researchers do ?

Answer 3

compared an adopted child, who later developed schizophrenia, with their birth parents and their adoptive parents.

Question 4

how many adoptees were examined in total ?

Answer 4

303

Question 5

where were all the adoptees from ?

Answer 5

Finland

Question 6

how many of the adopted children had biological mothers with schizophrenia ?

Answer 6

145 - adoptee considered as having a ‘high-risk’ for developing schizophrenia, genetically speaking

Question 7

how many adoptees had biological mothers without a psychiatric history ?

Answer 7

158 - adoptee considered as having a ‘low-risk’ of developing schizophrenia, genetically speaking

Question 8

what did the researchers determine about each adoptee’s adoptive family ?

Answer 8

whether the adoptee’s family was ‘healthy’ or ‘disturbed’

Question 9

what did the adoptee’s family need to be like, to be considered ‘disturbed’ ?

Answer 9

if the family exhibited a lot of criticism, conflict and a lack of problem-solving skills

Question 10

what did the adoptee’s family need to be like, to be considered ‘healthy’ ?

Answer 10

healthy families were found to be supportive environments, with parents having good coping mechanisms and problem-solving skills

Question 11

what were the findings of the adoptees whose mothers had schizophrenia AND who had been raised in a ‘disturbed’ environment ?

Answer 11

they were much more likely to develop schizophrenia (36.8%) than the adoptees whose biological mothers had schizophrenia but had been raised in a healthy environment (5.8%)

Question 12

what is important to note about the significant difference in probabilities in developing schizophrenia between the adoptees who all had biological mothers with schizophrenia but either were raised in a ‘disturbed’ or ‘healthy’ environment ?

Answer 12

both were considered a ‘high risk’, genetically speaking, of developing schizophrenia, so this emphasises the significance of being raised in a ‘disturbed’ or ‘healthy’ environment - suggests that genetics are not the sole reason for developing schizophrenia

Question 13

what were the findings of adoptees with biological mothers who didn’t have a psychiatric history ?

Answer 13

• those raised in a ‘disturbed’ environment had 5.3% chance of developing schizophrenia
• those raised in a ‘healthy’ environment had a 4.8% chance of developing schizophrenia

Question 14

what can be concluded from tienari et al. (2004) ?

Answer 14

because the adoptees who were a high genetic risk were likely to develop schizophrenia ONLY if they were raised in a ‘disturbed’ home environment, this supports the diathesis-stress explanation of schizophrenia

Question 15

what does the conclusion of tienari et al. (2004) mean ?

Answer 15

it means that both genetic vulnerability and environmental stress are necessary for schizophrenia to develop - genes alone cannot be the only factor for schizophrenia