The Interactionist Approach to Schizophrenia

Question 1

What is the interactionist approach?

Answer 1

• A way to explain the development of behaviour in terms of a range of factors, both biological and psychological ones.
• These factors combine and interact to develop the behaviour

Question 2

What is the diathesis stress model?

Answer 2

• An interactionist approach to explaining behaviour
• e.g. SZ is explained as a result of both an underlying vulnerability (diathesis) and a trigger (stressor), both of which are necessary for the onset of SZ

Question 3

What is the Meehl’s model?

Answer 3

• In the original diathesis-stress model, a diathesis was entirely genetic, a single ‘schizogene’, this led to the idea of a biologically based schizotypic personality, a characteristics being sensitivity to stress
• If a person doesn’t have the schizogene then no amount of stress would lead to SZ. But in carriers of the gene, chronic stress through childhood would lead to the development of SZ

Question 4

Describe the modern understanding of diathesis

Answer 4

• Modern views of diathesis include a range of factors beyond genetics, such as psychological trauma.
• Read et al proposed a neurodevelopmental mode, where early and severe enough trauma (diathesis) can affect brain development

Question 5

Describe the modern understanding of stress

Answer 5

• Stress was seen a psychological in nature, but a modern definition includes anything that risks triggering SZ
• Recent research into factors triggering SZ has concerned cannabis use. Cannabis may be a stressor as it increases the risk of SZ by up to 7 times, as it interferes with the dopamine system
• But, most people don’t develop SZ after smoking cannabis as they lack the vulnerability

Question 6

Describe treatment according to the interactionist model

Answer 6

• The model is linked with combining antipsychotics and psychological therapies, commonly CBT.
• In Britain, it’s increasingly standard practice to treat people with SZ with a combination of antipsychotics drugs and CBT

Question 7

Give evaluation for the interactionist approach (support for the role of both vulnerability and triggers)

Answer 7

• Tienari et al studied the impact of genetic vulnerability and a psychological trigger (dysfunctional parenting). There were children whose biological mother has SZ (high genetic risk group), and in adulthood they were compared to a control group of adoptees with no family history of SZ
• Adoptive parents had been assessed for child-rearing style and it was found high levels of criticisms and hostility (EE) were strongly associated with the development of SZ, but only in high genetic risk group.
• Shows that a combination of genetic vulnerability and family stress can lead to greatly increases risk of SZ

Question 8

Give evaluation for the interactionist approach (original diathesis-stress model is oversimplistic)

Answer 8

• The original model portrayed diathesis as a single schizogene and portrayed stress schizophrenogenic parenting
• It’s now clear that multiple genes and psychological factors influence and that stress comes in many forms and can be biological as well as psychological. This is shown in Houston et al’s study, where childhood sexual abuse emerged as the influence on diathesis to SZ and cannabis use as the major trigger
• This means that there are multiple factors affecting both diathesis and stress, supporting the modern understanding of both diathesis and stress

Question 9

Give evaluation for the interactionist approach (real-world application in the combination of biological and psychological treatments)

Answer 9

• Tarrier et al randomly allocated participants to (1) medication + CBT, (2) medication + counselling, or (3) control group with medication only. Those in the combination groups showed lower symptoms than control group, but there was no difference in hospital readmission
• Shows a clear practical advantage to adopting an interaction approach to SZ in terms of treatment
• However, Jarvis and Okami point out that saying a successful treatment for mental disorder justifies a particular explanation is a logical error (treatment-causation fallacy). So we can’t automatically assume that the success of combined therapies means interactionist explanations are correct