Interactionist approach

Question 1

Outline Meehl’s original diathesis-stress model.

Answer 1

Diathesis
(vulnerability)
Genetic predisposition - the result of a single ‘schizogene’, which led to a biologically based schizotypic personality which was extremely sensitive to stress.
+
Stress
(trigger)
Stress in childhood or adolescence e.g. poor parenting due to Schizophrenogenic mother

Question 2

Outline the new/modern diathesis stress model.

Answer 2

Diathesis
(vulnerability)
Genetic predisposition - is due to combination of genes
Psychological trauma - leads to changes in the developing brain. Read et al (2001) neurodevelopmental model - e.g. trauma causes the hypothalamic-pituitary-adrenal (HPA) system to becomes overactive which makes a person more vulnerable to stress
+
Stress
(trigger)
Poor parenting
Cannabis use – increases risk by up to 7 times as THC impacts the dopamine system
Environment e.g. urbanisation -living in a capital city are at an increased risk

Question 3

Outline treatment according to the interactionist approach.

Answer 3

Turkington et al. – we can still believe that schizophrenia has a biological basis but use CBT to relieve the psychological symptoms.

UK – it is perfectly acceptable to use a combination of both therapies.
USA – conflict between biological and psychological therapies which has led to slower adoption of the interactionist model. Medication alone is more common.

Question 4

What are the strengths of the interactionist approach to schizophrenia?

Answer 4

+ Research support: Tienari et al (2004) investigated the impact of both genetic vulnerability and a psychological trigger. Studied 19,000 Finnish children whose biological mothers had been diagnosed with schizophrenia. In adulthood they were compared to a control group without a genetic vulnerability. Adoptive parents who showed high levels of criticism and verbal hostility were strongly associated with the development of schizophrenia, but only in the genetic risk group. Suggests combination of genetic vulnerability and family stress can lead to greatly increased risk of schizophrenia.
+ Real world application: acknowledging both genetic and environmental risk factors has contributed to treatment methods. For example, researchers found that a combination of CBT or counselling and medication had reduced symptoms much more than a control group that used just medication. Suggests there is an advantage to adopting an interactionist approach to treating the disorder.
+Urbanicity: higher levels of schizophrenia in cities supports the interactionist approach as it suggests urban life is more stressful and acts as a trigger.

Question 5

What are the limitations of the interactionist approach?

Answer 5

• Diathesis and stress are complex. The model may oversimplify, multiple genes in combination can impact vulnerability. Stress can be biological and psychological. This means that there are multiple factors, both biological and psychological affecting both diathesis and stress. Supports the modern understanding and refutes original model.
• Treatment-causation fallacy: successful treatment does not justify a particular explanation. For example, because alcohol reduces shyness we cannot come to the conclusion that shyness is caused by a lack of alcohol.
• Urbanicity refuted: it may be that schizophrenia is more likely to be diagnosed in cities, or that people with a diathesis for schizophrenia are more likely to migrate to cities.