eval integrationist model

Question 1

Support for vulnerability and triggers

Answer 1

One strength of the interactionist approach to schizophrenia is evidence supporting the role of both vulnerability and triggers.
In a large-scale study, Pekka Tienari et al. (2004) investigated the impact of both genetic vulnerability and a psychological trigger (dysfunctional parenting). The study followed 19,000 Finnish 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 had been assessed for child-rearing style and 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 combination of genetic vulnerability and family stress can lead to greatly increased risk of schizophrenia.

Question 2

Diathesis and stress are complex

Answer 2

One limitation of the original diathesis-stress model is oversimplicity.
It is now clear that the original model that portrayed diathesis as a single schizogene and portrayed stress as schizophrenogenic parenting is hopelessly simplistic. Multiple genes in multiple combinations influence diathesis. Stress also comes in many forms, including but not limited to dysfunctional parenting. In fact diathesis can also be influenced by psychological factors and stress can be biological as well as psychological. This is shown in a study by James Houston et al. (2008), in which childhood sexual abuse emerged as the major influence on underlying vulnerability to schizophrenia and cannabis use as the major trigger.
This means that there are multiple factors, both biological and psychological, affecting both diathesis and stress, supporting the modern understanding of both diathesis and stress.

Question 3

Real-world application

Answer 3

One further strength of the interactionist approach is in the combination of biological and psychological treatments.
A practical application of acknowledging biological and psychological factors in schizophrenia has been the combination of drug treatment and psychological therapies. Studies show that combining treatments enhances their effectiveness.
For example Nicholas Tarrier et al. (2004) randomly allocated 315 participants to
(1) medication + CBT, (2) medication + counselling, or (3) control group (medication only). Participants in the two combination groups showed lower symptoms following the trial than the medication-only group, though there was no difference in hospital readmission.
This means that there is a clear practical advantage to adopting an interactionist approach to schizophrenia in terms of superior treatment outcomes.

Question 4

Counterpoint

Answer 4

Matt Jarvis and Paul Okami (2019) point out that saying that a successful treatment for mental disorder justifies a particular explanation is the logical equivalent of saying that because alcohol reduces shyness, shyness is caused by lack of alcohol. This logical error is called the treatment-causation fallacy.
Therefore we cannot automatically assume that the success of combined therapies means interactionist explanations are correct.