Lesson 6: Interactionist Approach In Explaining The Onset And Treatment For SZ

Question 1

What is the interactionist approach?

Answer 1

• The interactionist approach is an approach that acknowledges there are biological, psychological and societal factors in the development of SZ. Biological factors include genetic vulnerability and neurochemical (dopamine) and neurological (brain) abnormality. Psychological factors include stress, resulting from life events and daily hassles, including poor quality interactions in the family.

Question 2

Diathesis stress model: meaning

Answer 2

• diathesis means vulnerability, we have seen that SZ has a genetic component in terms of vulnerability
• in this context, stress simply means a negative psychological experience
• model states both a vulnerability to SZ and a stress-trigger are necessary in order to develop the condition
• one or more underlying factors make a person particularly vulnerable to developing SZ but the onset of the condition is triggered by stress

Question 3

Meehl’s model

Answer 3

• in the original diathesis-stress model (Meehl-1962) diathesis was entirely genetic and there was one specific gene ‘schizogene’

Question 4

Modern understanding of diathesis

Answer 4

• clear that many genes increase genetic vulnerability and there is no single gene. Modern views of diathesis include genes but also psychological trauma (Ingram and Luxton, 2005) so trauma becomes the diathesis rather than the stressor

Question 5

Read et al (2001)

Answer 5

• proposed a neurodevelopmental model in which early traumas affects brain development. In fact, early and severe enough trauma such as child abuse can seriously affect brain development e.g (hypothalamic pituitary adrenal) systems can become overactive making the person more vulnerable to stress

Question 6

Modern understanding of stress

Answer 6

• anything that risks triggering schizophrenia e.g. cannabis use which makes it 7 times more likely for a person to develop schizophrenic symptoms. This is because cannabis interferes with the dopamine system - although most people do not develop SZ through cannabis use as most people do not take cannabis but will develop SZ - this suggests that there are clearly other stressors which contribute to the development of SZ

Question 7

Treatment of SZ according to interactionist model

Answer 7

• interactionist model acknowledges both biological and psychological factors in SZ and is therefore compatible with both biological and psychological treatments
• in particular, combing anti-psychotic medication and psychological therapies such as CBT
• in Britain, it is increasingly standard practice to treat patients with a combination of drugs and CBT
• this is because SZ is a complex psychotic disorder, drug therapy given first to control symptoms (used in hospital setting) perhaps with token economy (to manage the behaviour of patients)
• CBT and family therapy precedes this

Question 8

Strengths of Interactionist approach

Answer 8

+ There is evidence for the role of vulnerability and triggers - there is research support for the dual role for genetic vulnerability to SZ and stress triggers. For example, Tienari et al (2004) studied children adopted away from schizophrenic mothers. The adoptive parents’ parenting styles were assessed and compared with a control group of adoptees with no genetic risk. A child-rearing style with high levels of criticsm and conflict and low levels of empathy was implicated in the development of schizophrenia but only for children with a high genetic risk. This is very strong direct support for the interactionist approach - genetic vulnerability and family-related stress combine in the development of SZ.

+ Support for the effectiveness of combination of treatments - another strength is the usefulness of the interactionist approach in treatment of SZ - Tarrier et al (2004) randomly allocated 315 patients to (1) medication and CBT group or (2) a medication and supportive counselling group, or (3) a control group. Patients in the two combination groups (group 1 and 2) showed lower symptom levels than those in the control group (medication only) but no differences in hospital readmission. Studies like this show that there is a clear practical advantage to adopting an interactionist approach in the form of superior treatment outcomes.

Question 9

Limitations of the interactionist approach

Answer 9

• One limitation is that the original diathesis-stress model is too simplistic- multiple genes increase vulnerability, each with a small effect on its own - there is no schizogene. Stress comes in many forms, including dysfunctional parenting. Researchers now believe stress can include biological factors. For example, Hudson et al found childhood sexual trauma was a diathesis and cannabis use was a trigger. This shows that the old idea of diathesis as biological and stress as psychological has turned out to be overly simple.
• Another limitation is we don’t exactly know how diathesis stress work - there is strong evidence to suggest that some sort of underlying vulnerability coupled with stress can lead to schizophrenia. But we don’t understand the mechanisms by which symptoms of schizophrenia appear and how both vulnerability and stress produce them. This does not undermine support for the approach but it does mean we have an incomplete understanding of the actual medication.
• Another limitation is the treatment-causation fallacy - Turkington et al (2006) argue the fact that combined biological and psychological therapies are more effective than either on their one does not necessarily mean the interactionist approach to schizophrenia is correct. Similarly the fact that drugs helps does not mean schizophrenia is biological in origin. This error of logic is called the treatment-causation fallacy. It means that the superior outcomes of combined therapies should not be over-interpretation in terms of evidence in support of the interactionist approach.