what does the interactionist approach consist of
psychological and biological explanations interacting with each other to cause Sz
what model does the interactionist approach to Sz use
diathesis-stress
what is the original diathesis model (Meehl)
- diathesis was entirely genetic - a ‘schizogene’
- if someone doesn’t have the gene, no amount of stress would make them develop Sz
- in carriers, stressors include a stressful childhood and a schizophrenogenic mother could result in Sz development
how can Meehl’s original ideas be flawed
- Sz is polygenic, with up to 108 candidate genes
- therefore the original diathesis is too simplistic, no ‘schizogene’
what is the modern understanding of diathesis
nowadays understood that there are also other psychological factors, other than family interactions, appearing to make someone more likely to develop it
what is the HPA system
the HPA system, with early severe trauma e.g. child abuse, can become overactive and make a person much more vulnerable to stress in later life
what is the modern understanding of stress
a modern definition includes anything that risks triggering Sz, such as cannabis (up to 7x in certain doses)
why does cannabis often lead to higher Sz development risks
cannabis increases dopamine, hyperdopaminergia, positive Sz symptoms, or the troughs will lead to hypodopaminergia
what’re 2 strength evals for the interactionist approach
+ Tienari
+ survey on Sz patients
how is Tienari’s adoption study a support for the interactionist approach of Sz
- studies 19,000 Finnish children; 145 were adoptees with at least 1 biological Sz parent adopted into a new family
- child-rearing style was assessed and compared to a control group
- found high levels of criticism/conflict in rearing style were implicated in Sz development but only in high-genetic-risk group, lower risk in low child risk but high genetic risk group
- shows a combination of genetic vulnerability and family stress can lead to greatly increased Sz risk
how is Sz survey a support for the interactionist approach
- in a surgery on Sz patients: 543 reported childhood sexual abuse and 643 reported cannabis use before 16 years old
what is a limitation of the interactionist approach
- ‘schizogene’ is oversimplified
- up to 108 candidate genes have now been found proving the original diathesis model to be a vast oversimplification/unable to fully explain the cause of Sz, weakening the basis
