Interactionist Explanations

• What are the psychological explanations?

  • The cognitive explanation
  • The family dysfunction explanation
• What are the biological explanations?

  • The genetic explanation
  • The dopamine hypothesis
  • The neural correlates explanation
• The interactionist explanation of schizophrenia says that…

  .... schizophrenia is caused by an interaction between biological factors and psychological factors.
• What does Diathesis mean?

  When someone is predisposed to developing the illness
• A person having a diathesis for schizophrenia means that they carry biological risk factors that make them more likely to develop schizophrenia.
• When we looked at the diathesis-stress model in Issues & Debates, we saw that it was an example of a gene-environment interaction.
• According to the diathesis-stress model...

  • People with a diathesis only develop schizophrenia if they experience enough psychological stress in their environment.
  • Biological factors act as a risk factor that gives people a diathesis for developing schizophrenia.
  • The more stress people have, the more likely they are to develop schizophrenia.
  • The more diathesis people have, the more likely they are to develop schizophrenia.
• Support for the diathesis stress model

  Tienari et al - adoption study comparing kids whose biological mums had SZ compared to a control group. Children whose mums had SZ were more likely to develop the disorder meaning that gene alleles they inherited were are a diathesis for SZ. But the childs risk of developing SZ also depended on the environment they grew up in, children only developed SZ if they experienced stress in their adopted family (acting as a trigger).
• Further support for the interactionist approach

  Brown and Birley 1968 conducted interviews with patients who had recently developed schizophrenia, they found that 50% of patients had a stressful life event in the three weeks prior to the symptoms starting. Supports the idea that stress triggers SZ.
• The interactionist approach to treating SZ involves giving the patient a combination of treatments.

  Patients are given antipsychotic drugs to treat positive symptoms, and CBT to reduce dysfunctional mental processes and reduce the negative symptoms.

  Finally, the patients and their families also go through family therapy to prevent relapse and help reduce the stressful family environment that triggered SZ.
• Evaluation of the interactionist approach to treating SZ

  A strength of this approach to treating SZ is that it is supported by a randomised controlled trial conducted by Guo et al, which showed that combining medication and therapy is more effective at treating SZ than just using medication. But one limitation of this approach is that combining treatments is expensive. Although a counter argument to this limitation is that it may be cost effective in the future as patients are less likely to return to hospitals.