An Interactionist Approach - The Diathesis-Stress Model

What is the diathesis-stress model?

Sz is a result of interaction between biological and psychological/environmental influences

Modern understanding on diathesis?

* Range of factors beyond genetic - e.g. psychological trauma = trauma the ‘diathesis’ rather than the ‘stressor’
* Epigenetics - genes turn on and off based no experience - may have an effect on vulnerability

Modern understanding on stress?

* Anything which could trigger the onset of the disorder
* Varese et al found kids who experienced severe trauma before 16 were 3 times more likely to develop sz

How do you treat schizophrenia with an interactionist approach?

* Uses a combination of both CBT and drug therapies
* Tarrier - 315 randomly allocated drugs + CBT, drugs + counselling or control \n combination - showed lower symptom levels although no difference in readmissions

Supporting Evidence?

* Tienari investigated genetic vulnerability and parenting style of 19k Finnish adoptees of mums with sz 1960-79 - assess child raising practice and rates of sz compared to control group
* High criticism, low empathy - likely to develop sz \n suggesting genes and stress are important in development
* Strong direct support for interactionist

Is the diathesis model oversimplified?

* Emphasises vulnerability as genetic alone - however risk can also come from environmental experiences. Houston - found childhood sexual abuse was a vulnerability that lead to changes in ability to cope with stress
* Original model was over simplified as it ignored complexity of diathesis factors

What is the treatment causation fallacy?

* Just because combination therapy is effective it doesn’t mean the interactionist approach is correct.
* Could be that some therapies improve engagement - therefore improving success