The Interactionist Approach

Question 1

Interactionist approach

Answer 1

The view that processes of nature and nurture work together rather than in opposition. Researchers study how nature and nurture interact and influence each other.

Question 2

Diathesis stress model

Answer 2

This is one conceptualisation of the interactionist approach that allows us to explain behaviours such as mental illness using the model of biological/genetic vulnerability (diathesis) interacting with an environmental influence (stressor) in order to produce a behaviour.

Question 3

Traditional diathesis stress model

Answer 3

Meehl - Individuals inherit a single genetic diathesis (vulnerability) for SZ known as a schizogene. If they don’t inherit this gene, they will not develop SZ. However, if they do possess the gene and experience stress in childhood, this can lead to the development of SZ.

Question 4

Modern view of diathesis

Answer 4

Multiple schizogenes (over 100 according to Ripke) as well as a psychological vulnerabilities such as trauma as a diathesis, rather than a stressor. This is because early and severe trauma (e.g. child abuse) can affect brain development.

Question 5

Modern view of stress

Answer 5

Includes cannabis use, which is a stressor as it increases the risk of SZ by up to seven times. This is likely to be a biological stressor, due to cannabis’ interference with the dopamine system.

Question 6

Treatment

Answer 6

We have evidence for a biological cause and also for a psychological cause, so it’s important to combine treatment. Turkington et al state that it is possible to believe in biological causes of SZ and still practice CBT to relieve psychological symptoms. This requires an interactionist approach.

Question 7

+ P - Research support

Answer 7

E - Tienari et al studied 9,000 Finnish mothers and adoptees who suffered from SZ and compared these findings to a
neurotypical group of children adopted across the same period.
E - They found that found that “in adoptees at high genetic risk of schizophrenia, but not in those at low genetic risk,
adoptive-family ratings were a significant predictor of schizophrenia-spectrum disorders in adoptees at long-term follow-up”.
L - Therefore, this provides strong support for the diathesis-stress model
because the findings demonstrate that a single diathesis or stressor is not enough to trigger the development of SZ, but rather a combination of the two is required.

Question 8

• P - Original diathesis-stress model is oversimplified

Answer 8

E - Ripke et al demonstrated that there are over 108 candidate genes, each slightly increasing the risk of SZ, and so there is no single ‘schizogene’.
E - Stress can come in many forms apart from the schizophrenogenic mother, such as high levels of expressed emotion, childhood trauma (Read et al).
L - Therefore, the diathesis is not
exclusively biological, nor is the stressor exclusively psychological.

Question 9

+ P - Research support

Answer 9

E - Tarrier et al studied
315 patients who were randomly allocated to one of three conditions, where the last control group received no treatment and the first two groups received a combination of psychological and biological
treatments.
E - They found that there were significant 8
advantages for CBT and supportive counseling over TAU (treatment as usual) alone on symptom measures at 18 months but no group difference was seen for relapse or re-hospitalisation.
L - Therefore, adjunctive psychological treatments can have a beneficial long-term effect on symptom reduction”.