Schizophrenia - Interactionist approach

Question 1

What is the interactionist approach in explaining schizophrenia?

Answer 1

Acknowledges that there are biological, psychological and societal factors in the development of schizophrenia.
Biological: Genetic vulnerability
Psychological and societal: Stress resulting from life events and daily hassles, including poor quality interactions in the family

Question 2

How does the diathesis-stress model explain the cause of schizophrenia?

Answer 2

A biological vulnerability to schizophrenia and a stress trigger are necessary to develop the disorder.

One or more underlying factors make a person vulnerable but the onset of the condition is triggered by stress.

Question 3

What was the original diathesis-stress model like?

Answer 3

• Said diathesis was entirely genetic, the result of a single ‘schizogene’.
• If a person doesn’t have the schizogene then no amount of stress will lead to schizophrenia
• The gene interacting with stress through childhood and adolescence results in schizophrenia

Question 4

What is the modern understanding of diathesis?

Answer 4

• Many genes increase genetic vulnerability
• There is no ‘schizogene’
• Modern views of diathesis also include a range of factors beyond the genetic, including early psychological trauma - trauma becomes the diathesis rather than the stressor
• Found that early trauma meant that brain architecture did not develop as it should
• This gives the individual a biological vulnerability to schizophrenia as they are more sensitive to stress later in life

Question 5

What is the modern understanding of stress?

Answer 5

• Originally stress was seen as psychological in nature, in particular related to parenting
• Psychological stress is still seen as important but a modern definition of stress includes anything that risks triggering schizophrenia including biological factors such as a virus or cannabis
• Cannabis users 2.5x more likely, heavy users 6x more likely to develop schizophrenia
• 7x the risk if mother had influenza virus during pregnancy

Question 6

What is the limitation of the original diathesis-stress model?

Answer 6

• It is over-simplified
• Original model said diathesis came only from having a schizogene but now we know if it many genes
• Also, early trauma can alter architecture of the brain and give biological vulnerability
  Original model says stress came from a family causing psychological stress, but now we know biological stress from environment such as viruses or cannabis use

Question 7

What is a strength of the diathesis-stress model as an explanation for schizophrenia?

Answer 7

Research support

• Large prospective study of adopted children
• Compared biological children of schizophrenic mothers with the biological children of non-schizophrenics
• First group was much more likely to be schizophrenic
• But only if the adoptive family they were brought up in was rated as disturbed - high conflict and criticism and low empathy
• It shows both biological vulnerability and environmental stress are needed