The interactionist approach to SZ

Question 1

What is meant by an interactionist approach to schizophrenia?

Answer 1

• also known as the biosocial approach is approach that takes into account both biological (e.g. genetic vulnerability) & psychological (interactions with family) factors when considering the development of SZ and the treatment of SZ

Question 2

What does the diathesis stress model argue?

Answer 2

• one way to present an interactionist approach
• diathesis means vulnerability while stress means a negative experience
• model says that both a vulnerability to SZ and a stress trigger are necessary in order to develop the disorder > onset of condition triggered by stress

Question 3

What did Meehl’s original diathesis stress model argue?

Answer 3

• original diathesis-stress model, as proposed by Meehl would now be considered outdated
• He proposed that the diathesis (vulnerability) is biological in origin (i.e. a single ‘schizogene’) which
  causes a schizotypic personality which in turn manifests itself as schizophrenia
• however this only occurs when the diathesis is accompanied by a purely psychological stressor (excessive exposure to stress, particularly through the schizophrenogenic mother)

Question 4

What is the modern understanding of diathesis?

Answer 4

• The renewed, modern understanding of diathesis is that it need not be biological in origin but could also be psychological, such as in the form of childhood trauma, as suggested by Ingram & Luxton
• The idea of a single schizogene has also been refuted by Ripke’s finding of over 108 candidate genes
• Read et al also proposed a neurodevelopment model in which early trauma alters the developing brain such as child abuse> e.g. the hypothalamic-pituitary gland (HPA) system can become overactive, making a person more vulnerable to stress & developing SZ

Question 5

What is the modern understanding of stress?

Answer 5

• includes anything that risks triggering schizophrenia > Houston et al not just parenting
• recent research focus on cannabis use which is a stressor > as it triggers the risk of schizophrenia by up to 7 times
• because cannabis interferes with the dopamine system

Question 6

What does treatment according to the interactionist model combine?

Answer 6

• combines antipsychotic medication and psychological therapies most commonly CBT
• If, according to the diathesis-stress model, both psychological & biological explanations apply to SZ, then it also follows that the same approach should be used in SZ treatment
• This is particularly the case as biological treatments appear to address the (direct) distal causes of SZ, whilst psychological treatments appear to be more well-suited in treating the (indirect) proximal causes, as suggested by Turkington et al
• Such an approach is likely to be reflected in the use of antipsychotic medication with CBT

Question 7

How does treatment vary between the US and the UK?

Answer 7

• Britain > standard practice to treat people diagnosed with SZ with a combination of antipsychotic drugs & CBT
• US > there is a history of conflict between psychological & biological models of SZ leading to a delayed adoption of an interactionist approach > medication only is more common in the US

Question 8

What is a strength of the interactionist approach to SZ?

Answer 8

• evidence supporting the role of both vulnerability & triggers
• Tienari investigated the impact of both genetic vulnerability & a psychological trigger (dysfunctional parenting)
• study followed Finnish adoptees whose biological mothers had been diagnosed with SZ
• this high genetic risk group were compared to a control group of adoptees without a family history of SZ (low genetic risk)
• adoptive parents had been assessed for child rearing style & it was found that high levels of criticism, hostility etc. were strongly associated with the development ofSZ but only in the high genetic risk group
• this shows that a combination of genetic vulnerability & family stress can lead to greatly increased risk of SZ

Question 9

What is a limitation of the original diathesis stress model?

Answer 9

• its simplicity
• the original model (Meehl) that portrayed diathesis as a single schizogene & portrayed stress as schizophrenogenic parenting is overly simplistic
• multiple genes in multiple combinations influence diathesis & stress also comes in many forms
• also seen that stress can be biological as well as psychological > this is shown in Houston et al study where childhood sexual abuse was a major influence on underlying vulnerability to SZ & cannabis use as the major trigger
• means that multiple factors both biological & psychological affect both diathesis & stress >support the modern understanding of both diathesis & stress

Question 10

What is another strength of the interactionist approach?

Answer 10

• is in the combination of both biological & psychological treatments in SZ
• studies show that combining treatments enhances their effectiveness
• e.g. Tarrier et al randomly allocated p’s to either medication + CBT, medication + counselling or control group (medication only)
• p’s in the |two combination groups showed lower symptoms following the trial than the medication only group
• means that there is a clear practical advantage of adopting an interactionist approach to SZ in terms of superior treatment outcomes

Question 11

What is a counterpoint to the interactionist approach of SZ?

Answer 11

• Jarvis & Okami> argue that the success of treatment does not prove that the explanation behind it is correct
• This is called the treatment-causation fallacy
• Just because combined therapies (e.g., CBT + antipsychotics) work, it does not mean the interactionist (diathesis-stress) explanation is necessarily true.
• It’s like saying alcohol reduces shyness, so shyness must be caused by a lack of alcohol—a logical error.
• Therefore, effectiveness of treatment is not proof of the theory’s accuracy.