A01: The Interactionist Approach to SZ

• The Interactionist Approach to SZ

  • Def of interactionist approach
  • The diathesis-stress model
  • Treatment in the concept of this topic
• The diathesis-stress model:

  • Diathesis-stress model:
  • Meehl's Model
  • Modern understanding of diathesis
  • Modern understanding of stress
• Diathesis-stress model:

  Vulnerability + trigger = SZ

  • The diathesis-stress model suggests that schizophrenia results from an interaction between genetic vulnerability and environmental stress.
  • Diathesis means vulnerability.
  • Stress in this context refers to negative experiences that trigger the vulnerability.
  • The diathesis-stress model says both a vulnerability and a trigger are needed to develop SZ. Individually may not create SZ - it is the interaction that is key.

  Our understanding of this interaction has changed over time
• Meehl's model:

  Diathesis is genetic.

  • According to Meehl, diathesis (vulnerability) completely genetic
  • In OG diathesis-stress model, diathesis result of single 'schizogene' leading to schizotype personality who by nature more sensitive to stress.
  • Meehl (1962) said someone without gene never develop SZ, no matter amount stress they exposed to
  • Sz only develops in those with schizogene. Person with gene, vulnerable to effectors of chronic stress (in childhood) (especially if schizophrenogenic mother) could lead to development of Sz.
  • Schizogene necessary bit not sufficient for development of SZ.
• Modern understanding of diathesis

  • 21st century
  • Now believed that diathesis is not due to a single 'schizogene' (outdated) Instead it thought that many genes increase vulnerability/diathesis
  • Also, diathesis/vulnerability does not have to be genetic. It could be early psychological trauma affecting brain development.(Ingram & Luxton 2005)
  • Also E.G: Read (2001) showed how severe, early childhood trauma can actually alter a developing brain and the HPA (Hypothalamic-pituitary system) becomes overactive making a person more vulnerable to stress later in later life.
• Modern understanding of stress

  21st century: According to Houston, modern def of stress/stressor (in relation to diathesis-stress) anything that risks triggering SZ.

  • Can be psychological (e.g. parenting) or biological (e.g. cannabis use)
  • Parents no longer considered to be sole cause of stress but just one of many potential env triggers.
  • Cannabis thought to be one of biggest stressors, can increase risk of SZ up to 7x with use (depending on does) - probably coz it interferes with dopamine system. BUT: most people DONT develop sz after smoking cannabis so there must be multiple triggers.
• Treatment in the context of this topic?:

  • Treatment according to the interactionist model
  • USA VS UK
  • Problems treating Sz with ONLY DRUGS, ONLY CBT?
• Treatment according to the interactionist model:

  Antipsychotic drugs taken in COMBINATION with CBT.

  • If there are a combination of reasons for why someone develops sz then it will be necessary to have a combination of therapies to treat it - biological to treat the genetic component & psychological to treat the environmental.
  • But this requires adopting an interactionist model - it is not possible to adopt a purely biological approach, tell patients that their condition is purely biological (no psychological significance to their symptoms) and then treat them with CBT (Turkington et al 2006)
• Treatment according to the interactionist model:UK VS USA

  • UK adopts more interactionist approach compared to US:

  In Britain it is increasingly 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 SZ and this may have led to slower adoption of the interactionist approach.
• Problems treating Sz with ONLY DRUGS, ONLY CBT?

  What problems can you see with treating Sz with ONLY CBT DRUGS?

  • If there are env triggers that are likely to bring on an episode (which common for sz sufferers) then as stop soon taking drugs those triggers will continue to cause symptoms

  What problems can you see with treating Sz with ONLY CBT?

  • There is clear evidence to show the role of excess dopamine in sz symptoms & its hard to see how CBT could reduce those levels. So although a patient may understand the symptoms... they will still have them
• 1st card: Interactionist approach

  This approach acknowledges there are biological (e.g genetic vulnerability), psychological (e.g stress & family dysfunction) & social factors in the development of schizophrenia