INTERACTIONIST APPROACH: DIATHESIS-STRESS MODEL AO1 & AO3

Question 1

The IA acknowledges both biological and psychological factors and is compatible with both types of
treatment.

Answer 1

• It suggests that a genetic vulnerability to schizophrenia needs to be triggered by an
  environmental stressor in order to develop schizophrenia.
• Meehl Believed diathesis was entirely genetic, the result of a single ‘schizogene’.
• Also he suggested if a person doesn’t have the schizogene then no amount of stress would lead to schizophrenia.
• However, in carriers of the gene, chronic stress through childhood and adolescence, particularly a schizophrenic mother could result in schizophrenia.
• A modern understanding of the diathesis makes it that there is no single ‘schizogene’, and includes a range of factors beyond the genetic, including psychological trauma– trauma becomes the diathesis rather than the stressor.
• A modern understanding of stress shows that originally stress was seen as psychological in nature, in particular related to parenting. Stress includes anything that risks triggering schizophrenia
• For example, cannabis. Cannabis is a stressor because it increases the risk of schizophrenia by 7 x as it interferes with the dopamine system

Question 2

8 marker structure

Answer 2

• [The interactionist approach considers the combined effects of biological, psychological and social factorson the development of schizophrenia.
• The most well-known is the diathesis-stress model which was first proposed by Meehl (1962) who suggested that the diathesis (vulnerability) was entirely genetic and the result of a single ‘schizogene’.
• He said that if a person did not have the gene, they would not be able to develop schizophrenia, regardless of much stress they were exposed to.
• However, if someone did have the gene, then chronic stress
  through childhood and adolescence, maybe as a result of having a ‘schizophrenogenic mother’, would trigger the gene and result in schizophrenia.

Question 3

A strength of Meehl’s model is that there supporting research.

Answer 3

• For example, Tienari et al investigatedthe combination of genetic vulnerability and parenting style in children adopted from 19,000 Finnish mothers who had SZ themselves.
• A child-rearing style characterised by high levels of criticism and conflict and low levels of empathy was implicated in the development of SZ in children with high genetic risk but not in the control group.
• This supports the theory as it shows that being genetically predispositioned to SZ (schizogene) and triggered by an environmental stressor (family dysfunction) leads
  to SZ.
• This is an advantage as it increases the validity of the key assumptions made by Meehl

Question 4

A strength of the interactionist approach is that it has practical application of the diathesis stress model

Answer 4

• For example, Tarrier et al randomly allocated 315 patients to one of three groups: medication and CBT, medication and supportive counselling or a control group who only received medication.
• Patients in both combination groups showed lower levels of symptoms than the control.
• This shows that the combination of bio and psychological treatments are effective together as it targets both of their aspects of SZ.
• This is an advantage as it provides a more holistic treatment for SZ rather than only using drug therapy- and increased rate of recovery.

Question 5

A limitation of the interactionist approach is that it’s too simplistic.

Answer 5

• For example, we have well-informed suggestions of how vulnerabilities and stress might lead to SZ but we do not yet fully understand the mechanisms of how vulnerability and stress cause SZ.
• This suggests that the approach doesn’t explain how SZ is caused as its descriptive rather than explanatory.
• Therefore we are unable to pinpoint a root cause based on this approach.
• This is a disadvantage as an incomplete explanation of SZ will lead to limited treatments ultimately reducing the QOL of patients