Interactionist approach

Question 1

What is the interactionist approach?

Answer 1

a way to explain the development of behaviour in terms of a range of factors, or more specifically in schizophrenia. It acknowledges there are both biological factors (like genetic vulnerability and neurochemical/neurological abnormality) and psychological factors (like stress from e.g. life events) and social. Most importantly such factors don’t simply add together but combine in a way that can’t be predicted by each one separately i.e. they interact.

Question 2

What is meant by the term ‘diathesis’ as it applies to schizophrenia?

Answer 2

Diathesis is the underlying vulnerability for developing schizophrenia. We know now many genes each appear to increase genetic vulnerability slightly, rather than there being a single ‘schizogene’. Modern views also include a range of factors beyond the genetic, including psychological trauma, thus trauma becomes the diathesis, rather than the stressor.

Question 3

What is the diathesis-stress model?

Answer 3

an interactionist approach to explaining behaviour. For example, schizophrenia is explained as a result of both an underlying vulnerability (diathesis) and a trigger (stressor), both of which are necessary for the onset of schizophrenia. In early versions of the diathesis-stress model, vulnerability was genetic and triggers were psychological. Nowadays both genes and trauma are seen as diatheses, and stress can be psychological or biological in nature.

Question 4

What is meant by the term ‘stress’ as it applies to schizophrenia?

Answer 4

Stress would be seen as anything that may act as a trigger that would cause schizophrenia. Recent research into causes of schizophrenia includes cannabis usage. Cannabis is a stressor because it increases the risk of schizophrenia up to 7 times depending on the dosage. This may be because cannabis interferes with the dopamine system. However, most people do not develop schizophrenia after smoking it presumably because they last the requisite vulnerability factors (diathesis).

Question 5

Original theory diathesis

Answer 5

Entirely genetic.
Genes are assumed to cause neurochemical abnormalities (e.g. Dopamine levels being too low in the prefrontal cortex leading to too high levels in the subcortex) that in turn, result in an increased risk for schizophrenia.
If a person does not have the genetic vulnerability, no amount of stress would lead to schizophrenia.

Question 6

Revised theory diathesis

Answer 6

Later, this was revised to also include vulnerabilities due to childhood trauma which might have affected brain development. For instance, child abuse can alter the developing brain and act as a diathesis (vulnerability). The hypothalamic-pituitary-adrenal (HPA) system (chronic stress response) can become overactive, making a person much more vulnerable to later stress.

Question 7

Original theory stress

Answer 7

In Meehl’s original model, the stress (trigger) for schizophrenia was chronic stress in childhood and adolescence, in particular the schizophrenogenic mother. This is where the mother is cold, rejecting and controlling and the father is passive. This leads to tension and secrecy within the family and is thought to lead to psychotic thinking and paranoid delusions.

Question 8

Revised theory stress

Answer 8

Later this was revised to include any negative psychological experience that risks triggering schizophrenia e.g. dysfunctional parents (double bind, expressed emotion) and stressful live events (e.g. going to university, moving house, relationship breakdown, academic pressure, substance abuse etc.).
In terms of substance abuse, cannabis is a stressor because it increases the risk of schizophrenia by up to 7 times depending on the dose. This may be because it interferes with the dopamine system. But this only triggers schizophrenia in those with a vulnerability factor.
* Therefore, any negative psychological experience in someone who has a vulnerability could result in schizophrenia.

Question 9

Strength (dual role)

Answer 9

Tarrier et al. (2004) randomly allocated 315 patients to a medication + CBT, medication group + supportive counselling group or control group (medication only). They found that patients in the two combination groups showed lower symptoms levels than those in the control group, although there was no difference in rates of hospital readmission.

This suggests there is a clear practical advantage to adopting an interactionist approach in the form of superior treatment outcomes, and therefore highlighting the importance of taking an interactionist approach.
however, just because an interactionist treatment is successful, doesn’t necessarily mean the interactionist explanations of schizophrenia are correct. For instance, just because alcohol reduces shyness doesn’t mean that shyness is caused by a lack of alcohol. The same principle applies here and so from this research we can’t strongly support the interactionist explanations of schizophrenia.

Question 10

Weakness (simplicity)

Answer 10

It is now clear that portraying diathesis as a single gene and stress as schizophrenogenic parenting is overly simplistic. Multiple genes in multiple combinations have been found to act as diathesis, as well as brain damage caused by environmental factors. For example, Verdoux et al. (1998) estimated that the risk of developing schizophrenia later in life was four times greater for those who had experienced prolonged labour and oxygen deprivation than those who hadn’t experienced such complications. Stress has also been found to come in many forms, not just dysfunctional parenting. For example, Houston et al. (2008) found that childhood sexual abuse emerged as the major influence on underlying vulnerability to schizophrenia and cannabis use as the major trigger.

This suggests that both genetic vulnerability and family-related stress are important in the development of schizophrenia - genetically vulnerable children are more sensitive to parenting behaviour. This is strong direct support for the importance of adopting an interactionist approach to schizophrenia, including that poor parenting is a possible source of stress that triggers schizophrenia in those who are vulnerable.

Question 11

Strength (usefulness)

Answer 11

Maladaptive methods of coping with stress in childhood and throughout development means that the individual fails to develop effective coping skills, which in turn compromises their resilience and increases vulnerability. This may make life generally more stressful for the individual and so trigger schizophrenia.

This suggests that the old idea of diathesis-stress may be overly simple. However, it supports a modern interactionist approach to schizophrenia is important in that vulnerabilities and triggers seem to interact together in some way to produce schizophrenia. Although, most people do not develop schizophrenia after smoking cannabis and so it seems there must also be one or more triggering stressful factors, which means that from the model it is difficult to predict exactly who will develop schizophrenia.

Question 12

Weakness (difficult)

Answer 12

Tienari et al. (2004) studied 19000 Finnish children who had at least one biological parent with schizophrenia and were adopted into a new family and compared them with adoptees without this genetic risk. The adopted parents were assessed for child-rearing style and the rates of schizophrenia across the two groups was compared. They found that a child-rearing style characterised by high levels of criticism and conflict and low levels of empathy were implicated in the development of schizophrenia (dysfunctional parenting - psychological trigger), but only for those in the high-genetic-risk group. High-genetic-risk adoptees reared in families with low scores on this child-rearing style scale were significantly less likely to have developed schizophrenia than high genetic risk adoptees reared in families with high scores on the child-rearing style scale.

Therefore, it is extremely difficult to determine the causal stress that triggered schizophrenia, which may negatively impact the effectiveness of treatment.