the interactionist approach to schizophrenia

Question 1

explain Diathesis-stress model: vulnerability + trigger= schizophrenia

Answer 1

• diathesis means vulnerability
• in this context, stress refers to negative psychological experience
• so this diathesis-stress model says that both a vulnerability to schizophrenia and a stress trigger are necessary to develop the condition

Question 2

in the original diathesis-stress model, diathesis was entirely

Answer 2

• genetic, the result of a single ‘schizogene’; when an individual possessed this gene, they are vulnerable to the effects of chronic stress
• most notably, a schizophrogenic mother could result in the development of the condition
• the schizogene is necessary but not sufficient for the development of schizophrenia

Question 3

explain how a modern understanding of diathesis is that many genes increase vulnerability

Answer 3

• one way in which our understanding of diathesis has developed is that it is now clear that many genes each appear to increase genetic vulnerability; there is no ‘schizogene’
• diathesis does also not have to be genetic- it can also include early psychological trauma which seriously affects brain development
• for example, child abuse affecting the HPA system can be over-active, making them more vulnerable to stress

Question 4

explain how a modern understanding of stress includes anything that risks triggering the condition

Answer 4

• although psychological stress e.g. parenting is still important, a modern definition of stress includes anything that risks triggering schizophrenia
• much of recent research has concerned cannabis use which can increase the risk of schizophrenia up to 7x according to the dose; this is probably because it interferes with the dopamine system

Question 5

Explain how combining antipsychotic medication and CBT is consistent with the approach

Answer 5

• it is possible to believe in biological causes of schizophrenia and still practice CBT to relieve psychological symptoms
• however this requires adopting an interactionist approach
• it is not possible to adopt a purely biological approach, tell patients their condition is purely biological and then treat them with CBT

Question 6

Explain how the UK adopts a more interactionist approach compared to the US

Answer 6

• in Britain it is completely standard practice to treat patients with a combination of drugs and CBT
• in the US there is more of a conflict between psychological and biological models of schizophrenia
• this may have lead to a slower adoption of the interactionist approach

Question 7

What are the evaluation points for diathesis-stress model?

Answer 7

❌ original model is too simplistic
❌ we don’t exactly know how diathesis and stress work
✅ combats ‘chemical cosh’ issue associated with sole biological treatments
❌ treatment-causation fallacy

Question 8

Explain how the original model is too simplistic

Answer 8

• it is now known that multiple genes increase vulnerability to schizophrenia, each having a small effect on its owns there is no schizogene
• also stress can come in many forms, including, but not limited to dysfunctional parenting
• in fact it is now believed that stress can also include biological factors as childhood sexual trauma was a vulnerability factor whilst cannabis use could be a trigger
• this shows that the old idea of diathesis as biological and stress as psychological has turned out to be too overly simple

Question 9

Explain how we don’t exactly know how diathesis and stress work

Answer 9

• there is strong evidence to suggest that some sort of underlying vulnerability coupled with stress can lead to schizophrenia
• however we do not fully understand the mechanisms by which symptoms of schizophrenia appear and how both vulnerability and stress produce them
• this does not undermine evidence supporting the approach, but it does mean that it presents us with an incomplete understanding of the mechanism

Question 10

Explain treatment-causation fallacy

Answer 10

• there is good logical fit between the interactionist approach and combining therapies
• however the fact that combined biological and psychological therapies are more now effective than either on their own does not necessarily mean the interactionist approach to schizophrenia is correct
• similarly, the fact that drugs help does not mean schizophrenia is biological in origin; this error of logic is called treatment-causation fallacy
• it means that superior outcomes of combined therapies should not be over-interpreted in terms of evidence in support of the interactionist approach