Diathesis stress models Flashcards
What does evidence show?
There is no single factor that causes schizophrenia and it is unlikely different factors cause schizophrenia indecently as some develop SZ for genetic reasons and some due to drug taking
What is a likely explanation of schizophrenia?
Different factors interact so you need a combination of diathesis and stressors which both increase risk hugely
Who created the first diathesis stress model?
Methyl
What is Meehl’s diathesis stress model?
It is the development of psychodynamic explanation of schizophrenia informed by twin/adoption studies and role of genes
What is the diathesis of Meehl’s model?
A ‘schizogene’ is inherited, leading to schizotypal personality and a high vulnerability to stress
What is the stressor of Meehl’s model?
Schizophrenogenic mother increases stress and triggers development of schizophrenia
What is the second diathesis stress model?
Bleuler and Rosenthal
What is Bleuler and Rosenthal’s diathesis stress model?
The psychodynamic approach lost popularity so most researcher believed in a modified version
What is the diathesis of Bleuler and Rosenthal’s model?
Genes, which increase vulnerability to stress
What is the stressor of Bleuler and Rosenthal’s model?
Environment, such as family dysfunction or life events which trigger development of schizophrenia
What is evidence of Bleuler and Rosenthal’s model?
Tiernari
What was Tiernari’s study?
He used adoptees and measured genetic vulnerability with schizophrenia in the biological family, and environmental vulnerability with dysfunction parenting
How wad environmental vulnerability measured?
Criticism, hostility and low empathy
What was the percentage of those with low genetic risk and low dysfunctional parenting who had schizophrenia?
3.5%
What was the percentage of those with low genetic risk and high dysfunctional parenting with schizophrenia?
7%
What was the percentage of those with high genetic risk and low dysfunctional parenting who had schizophrenia?
7.5%
What was the percentage of those with high genetic risk and high dysfunctional parenting who had schizophrenia?
34%
How does Tienari’s study support the new model?
Genes and family stressors interact, when one factor is present there is only a small increase in risk and when both are present there is a large increase in risk
What does Tiernari’s study support?
The claim that there is an interaction between genetics and environment
What is the diathesis of the modern model?
Early factors
What are early factors?
Genes, abuse and pre-natal factors which increase vulnerability to stress
What are the stressors of the modern diathesis stress model?
Later factors
What are later factors?
Family factors, life stressors and drugs which trigger development of schizophrenia
What is evidence for the modern model?
Houston
What was Houston’s experiment?
Measured whether particapnts had experienced sexual trauma, used cannabis before 16 and whether they had developed psychosis
What was the percentage of participants who hadn’t use cannabis and has no sexual trauma with symptoms of psychosis?
0.5%
What was the percentage of participants who had used cannabis and has no sexual trauma with symptoms of psychosis?
0.6%
What was the percentage of participants who hadn’t use cannabis and has sexual trauma with symptoms of psychosis?
2.2%
What was the percentage of participants who had used cannabis and has sexual trauma with symptoms of psychosis?
12%
How does Houston’s study support the modern version of the diathesis stress model?
Sexual trauma and cannabis interact, supporting claim that there is an interaction between early and later factors
What is the importance of adopting an interactionist approach to explaining schizophrenia?
Can help implications or treatment, as if schizophrenia has multiple causes, it may need multiple treatments which each target different elements of the cause
