Interactionist Approach

Question 1

What does it acknowledge?

Answer 1

• There are biological and psychological factors which don’t simply add together but combine in a way that can’t be predicted by each one separately

Question 2

Diathesis-Stress Model

Answer 2

• Schizophrenia is caused by a vulnerability (diathesis) and trigger (stressor)
• One or more factors make a person particularly vulnerable to developing schizophrenia, but the onset of the condition is triggered by stress

Question 3

Meehl’s Model (1962)

Answer 3

• Diathesis was entirely genetic, the result of a single ‘schizogene’ – this led to the idea of a biologically based schizotypic personality, one characteristic of which is sensitivity to stress
• According to Meehl, if a person does not have the schizogene, no amount of stress would lead to schizophrenia; however, in gene carriers, chronic stress through childhood and adolescence (in particular the presence of a schizophrenogenic mother) could result in the development of disorder

Question 4

Modern Understanding Of Diathesis

Answer 4

• It is now clear that many genes each appear to increase genetic vulnerability only slightly, there is no single ‘schizogene’ (Ripke et al in 2014)
• Modern views of diathesis include a range of factors beyond the genetic, including psychological trauma (Ingram and Luxton in 2005) – trauma becomes the diathesis instead of the stressor

Question 5

Read et al (2001)

Answer 5

• Proposed a neurodevelopmental model in which early and severe enough trauma can alter the developing brain
• The hypothalamic-pituitary-adrenal (HPA) system can become overactive, making a person much more vulnerable to later stress

Question 6

Modern Understanding Of Stress

Answer 6

• Psychological stress is still important, but a modern definition of stress includes anything that risks triggering schizophrenia (Houston et al in 2008)
• Much of the recent research into factors triggering an episode has concerned cannabis use – cannabis is a stressor because it increases the risk of schizophrenia by up to 7x according to dose; this may be due to cannabis interfering with the dopamine system
• Most people don’t develop schizophrenia after smoking cannabis presumably because they lack the requisite vulnerability factors

Question 7

Treatment According To Interactionist Model

Answer 7

• Interactionist model is compatible with both biological and psychological treatments as it acknowledges those factors
• The model is associated with combining antipsychotic medication and psychological therapies (CBT)

Question 8

Turkington et al (2006)

Answer 8

• It is perfectly possible to believe in biological causes of schizophrenia and still practice CBT to relieve psychological symptoms, but it requires adopting an interactionist model
• It’s not possible to adopt a purely biological approach and tell people with schizophrenia that their condition is purely biological and that there is no psychological significance to symptoms, and then simultaneously treat them with CBT

Question 9

Evaluation - Tienari et al (2004) Procedure

Answer 9

• Investigated the impact of both genetic vulnerability and a psychological trigger (dysfunctional parenting)
• The study followed 19k children whose biological mothers had been diagnosed with schizophrenia – in adulthood, this high genetic risk group were compared to a control group of adoptees without a family history of schizophrenia (low genetic risk)
• Adoptive parents were also assessed for child-rearing style

Question 10

Evaluation - Tienari et al (2004) Findings & Conclusion

Answer 10

• It was found that high levels of criticism, hostility, and low levels of empathy were strongly associated with the development of schizophrenia, but only in the high genetic risk group
• This shows that a combo of genetic vulnerability and family stress can lead to greatly increased risk of schizophrenia

Question 11

Evaluation - Effectiveness of combining biological and psychological treatments (Tarrier et al (2004)

Answer 11

• Randomly allocated 315 participants to medication + CBT, medication + counselling, or control group (medication-only), and found that participants in the 2 combo groups showed lower symptoms following the trial than the medication-only group, yet there was no difference in hospital readmission
• There is a clear practical advantage to adopting an interactionist approach to schizophrenia in terms of superior treatment outcomes

Question 12

Evaluation - Jarvis & Okami (2019)

Answer 12

• Saying that a successful treatment for mental disorder justifies a particular explanation is a logical error known as the treatment-causation fallacy
• We can’t automatically assume that the success of combined therapies means interactionist explanations are correct