Diathesis-stress model

Question 1

What does the diathesis stress model suggest?

Answer 1

Schizophrenia is the result of an interaction between biological (diathesis) and environmental (stress) influences

Question 2

What evidence supports diathesis?

Answer 2

Family studies

Question 3

What evidence supports stress?

Answer 3

Varese et al found children who experienced severe trauma before the age of 16 were 3 times more likely to develop schizophrenia in later life compared to general population

Question 4

Why is a combination of diathesis and tree more likely to lead to the onset of schizophrenia?

Answer 4

minor stressors can lead to the disorder if individual is genetically highly vulnerable or a major stressful event might cause a similar reaction in a person low in vulnerability
Either combinations suggests the idea diathesis and stress add together to produce disorder

Question 5

What were the procedures of Tienari et al study?

Answer 5

Hospital records were reviewed for nearly 20,000 women admitted to Finnish psychiatric hospitals (1960-1979) - list checked to find mothers who had offspring adopted
Resulting sample of 145 was then matched with a sample of 158 adoptees without genetic risk
Both groups independently assessed after a median of 12 years (follow-up after 21 years)
They also assessed family functioning in adopted families using OPAS scale
Interviewing psychologists were kept blind to status of biological mother

Question 6

What were the findings of Tienari et al study?

Answer 6

Of the 303 adoptees, 14 developed schizophrenia - 11 were from the high risk group
However, being reared in a ‘healthy’ adoptive family appeared to have a protective effect even for those at high genetic risk

Question 7

What are the difficulties with determining casual stress?

Answer 7

Stressors earlier in life can also influence how people respond to later stressful events and increase their future susceptibility to the disorder
Hammen - maladaptive methods of coping with stress in childhood & throughout development means that the individual fails to develop effective coping skills = more stressful life and more likely to trigger mental illness

Question 8

What are the limitations of Tienari et al study?

Answer 8

Psychiatrists assessed stress in the adoptive family using the OPAS scale - this is assessing family function at one given time - fails to reflect developmental changes in family functioning over time making it impossible to determine how much of the tree observed is assigned to the family how how much is the adoptees themselves