The Interactionist Approach of explaining & treating Schizophrenia

What does the interactionist approach argue about Sz?

• There are biological and psychological/societal factors that contribute to the development of Sz

  • Biological factors = genetic vulnerabilities, neurochemical abnormality etc.

  • Psychological factors = stress, poor quality family interactions

Describe the diathesis-stress model

• Diathesis = underlying vulnerability

• Stress = trigger for the development of Sz

  • In the context of Sz, stress means a negative psychological experience

• The model suggests that an individual must have the genetic vulnerability and a stress-trigger present in order to develop the condition

  • An individual may have more than one underlying biological factor which would make them vulnerable but the onset is triggered by stress

Describe Meehls (1962) original model of Sz

• Diathesis was always biological and stress was always psychological

  • Diathesis was entirely genetic and the result of a single schizogene - resulting in a schizotype personality which was sensitive to stress

    • Chronic stress through childhood (e.g., presence of a schizophrenogenic mother) could result in the development of the condition in carriers of the gene

Describe the modern version of the diathesis-stress model

• Diathesis - biological or psychological (early or severe trauma)

  • Many genes have been linked to causing schizophrenia- polygenic

  • Early and severe trauma can effect the developing brain

    • HPA (hypothalamic-pituitary-adrenal) system becomes more over-active and this makes the person more vulnerable to later stress

• Stress can be caused by societal/psychological/biological factors

  • Recent research has looked at cannabis as a triggering “stress factor” as it increases the rate of Sz by 7 times

    • This may be because it interferes with the dopamine system

There is evidence to support the dual role of vulnerability and stress in the development of Sz. Describe how this is a strength of the interactionist approach to explaining Sz

• Tienari et al (2004): assessed adopted children whose biological mother was a sufferer of Sz compared to a control group of adoptees without any genetic risk

  • Parenting style characterised by high levels of criticism and conflict and low levels of empathy was implicated in the development of the disorder but ONLY for children with high genetic risk and not in the control group

• Varese (2012): children who experienced severe trauma before the age of 16 were 3x more likely to develop Sz compared to the general population

  • There was a relationship between level of trauma and the likelihood of developing Sz

• This is a strength as it suggests that both genetic vulnerability and psychological stress are important in the development of Sz

Twin studies offer further support for the interactionist approach. Describe how this is a strength of the interactionist approach as an explanation of Sz

• MZ twin concordance rates for Sz seldom rise above 50%

  • This supports the view that environmental factors must also play a role in determining whether a biological vulnerability actually develops into the disorder

• This is a strength as it demonstrates that genetic vulnerability alone doesn’t automatically lead to the disorder - we would expect 100% concordance if genes alone caused Sz

Describe the importance of an interactionist approach when treating Sz

• Sz is compatible with both biological and psychological treatments

  • The model would recommend it combine antipsychotic medication and psychological therapies (e.g., CBT)

    • Turkington (2006) believes it is possible to believe in biological causes of Sz and still practice CBT to relieve psychological symptoms

There is support for taking an interactive approach to treating Sz. Describe how this is a strength of the interactionist approach to treating Sz

• Tarrier (2004): studied 215 patients who were randomly allocated to 1 of 3 groups…

  • 1. Medication & CBT, 2. Medication & Counselling, 3. Control group (Medication only)

    • Tarrier found symptom levels were lower in both combination groups compared to the control group although there was no difference in rates of hospital re admission

• This is a strength as it clearly demonstrates the benefits of adopting an interactionist approach when treating Sz

Describe treatment-causation fallacy

• Turkington et al argued that there is a good logical fit between the interactionist approach and using a combination of treatments

  • The fact that combined treatments are effective doesn’t mean that the interactionist approach is correct

    • E.g., paracetamol can treat headaches but this doesn’t mean that low paracetamol levels cause them