The Interactionist Approach to Schizophrenia

Explain what is meant by the Interactionist approach to schizophrenia

The interactionist approach to schizophrenia says that the disorder is caused by a combination of biological and environmental (psychological, physiological and social) factors working together

Explain what is meant by the diathesis-stress model

Explains that schizophrenia develops due to a combination of vulnerability and environmental stress

• Diathesis: Vulnerability/predisposition to the disorder

• Stress: Environmental trigger for the disorder

Give 3 examples of ‘Diathesis’

• Genetics

• Neurochemistry

• Brain structure abnormalities

Give 5 examples of ‘Stress’

• Life events

• Early attachments

• Trauma

• Family interactions

• Drug use

What is the modern understanding of ‘Diathesis’?

• Many genes can give people a biological vulnerability to a condition

• ‘Diathesis’ can also include trauma that may alter the brain (E.g: early abuse may alter the brain’s response to stress making it oversensitive) → This makes the person more vulnerable to later stress

What is the modern understanding of ‘Stress’?

• ‘Stress’ can be anything that risks triggering Schizophrenia

• Including psychological stress (For example: life events, parenting)

What is an example of a physiological stress trigger?

Cannabis

Give an example of how diathesis and stress can lead to someone developing Schizophrenia

1. Someone may be biologically predisposed to have schizophrenia (e.g: have the PCM1 gene)

2. Won’t suffer from Schizophrenia until something in the environment triggers it

3. A life event such as a divorce could trigger Schizophrenia

4. People often need multiple risk factors to develop Schizophrenia

How does Gottesman’s research support the Diathesis-stress model?

Gottesman 1991 found concordance rate for Schizophrenia in MZ and DZ twins

• MZ twins: 48%

• DZ twins: 17%

Supports the Diathesis-stress model as higher concordance in MZ twins than DZ twins shows a genetic vulnerability (diathesis) is important

• However, the concordance is not 100% in MZ twins, even though they share identical genes

This means:

• Genes alone are not enough to cause schizophrenia

• Environmental stressors must also play a role

How does Tienari’s research support the Diathesis-stress model?

Tienari et al. (2004) conducted adoption research on Finnish adoptees

Findings:

• Adoptees at high genetic risk of schizophrenia (due to having parent/s with schizophrenia) are significantly more likely to develop schizophrenia if raised in a hostile family environment

• As opposed to:

  • Adoptees at high genetic risk of schizophrenia raised in healthy family environment

  • Adoptees at low genetic risk of schizophrenia raised in hostile family environment

  • Adoptees at low genetic risk of schizophrenia raised in healthy family environment

Suggests genes and environment are both important in the development of schizophrenia, supporting the diathesis-stress model

Explain a limitation PEEL plan of the Diathesis-Stress model

1. The diathesis–stress model is oversimplified

2. It does not explain how biological and environmental factors interact; research into epigenetics shows how the environment can influence gene expression

3. This means the relationship between diathesis and stress is more complex and dynamic than the model suggests

4. Therefore, the model lacks explanatory power as it does not fully account for how schizophrenia can be triggered

Why is combining drug therapy and psychological therapies a successful approach to treating schizophrenia?

If biological and psychological factors interact to lead to Schizophrenia it makes sense that treatment should be a combination of biological and psychological therapies

• Drugs reduce the overactivity of dopamine

• CBT and Family therapy reduce stress and triggers for Schizophrenia

How does Tarrier’s research support the effectiveness of combing treatments?

Tarrier et al. 2004

Procedure

• Schizophrenia patients randomly allocated to one of 3 groups

  1. CBT and medication

  2. Counselling and medication

  3. Medication only (control)

Findings

• Groups 1 and 2 showed lower symptom levels

• Supports benefits of interactionist approach to treatment

Where does the interactionist approach stand on the Holism/reductionism debate? Explain how?

Holism

• Has a more individual understanding of patient’s needs

• It considers both biological factors and environmental factors → explains schizophrenia as the interaction between multiple levels of explanation, rather than reducing it to one cause

How is it a strength that the Individualist Approach to Schizophrenia is holistic?

• It provides a more complete and realistic explanation of schizophrenia

• This can lead to more effective treatments, combining biological (drug therapy) and psychological (CBT) approaches