The interactionist approach

Question 1

What is the interactions approach?

Answer 1

• the interactions approach also sometimes called the biosocial approach is an approach that acknowledges that there are biological, psychological and societal factors in the development of schizophrenia
• biological factors include genetic vulnerability and neurochemical abnormality
• psychological factors include stress, for example, resulting from life events and daily hassles including poor quality interactions in the family

Question 2

What is the diathesis-stress model?

Answer 2

• diathesis means vulnerability
• in this context stress simply means a negative psychological experience
• the diathesis-stress model says that both a vulnerability to schizophrenia and a stress-triggering are necessary in order to develop the condition
• one or more underlying factors make a person particularly vulnerable to developing schizophrenia but the onset of the condition is triggering by stress

Question 3

What is Meehl’s model?

Answer 3

• in the original diathesis-stress model diathesis was entirely genetic, the result of a single schizogene
• this led to the development of a biologically based schizotypic personality, one characteristic of which is sensitivity to stress
• according to Meehl, if a person does not have the schizogene then no amount of stress would lead to schizophrenia
• however in carriers of the gene, chronic stress through childhood and adolescence, in particular the presence of a schizophrenogenic mother, could result in the development of the condition

Question 4

What is the neurodevelopmental model?

Answer 4

• Read et al proposed a neurodevelopmental model in which early trauma alters the developing brain
• early and servers enough trauma, such as child abuse, can seriously affect many aspects of brain development
• for example the hypothalamic-pituitary-adrenal system can become over-active, making the person much more vulnerable to later stress

Question 5

What is treatment according to the interactionist model?

Answer 5

• the interactionist model of schizophrenia acknowledges both biological and psychological factors in schizophrenia and is therefore compatible with both biological and psychological treatments
• Turkington et al point out that it is perfectly possible to believe in biological causes of schizophrenia and still practise |CBT to relieve psychological symptoms
• however this requires adopting an interactionist model; it is not purely biological and that there is no psychological significance to symptoms and to simultaneously treat them with CBT
• CBT family therapy and the use of token economies with sufferers of schizophrenia are usually carried out with patients taking antipsychotics

Question 6

What are the evaluation points of the interactions approach?

Answer 6

-finish adoption study
-stress can have many forms and so can genetic causes
+combining CBT, medication and counselling works
-we don’t know exactly how diathesis and stress work

Question 7

How is evidence for the role of vulnerability and triggers a weakness of the interactionist approach?

Answer 7

• there is evidence to support the dual role of vulnerability and stress in the development of schizophrenia
• Tienari et al investigated the combination of genetic vulnerability and parenting style which is the trigger
• children adopted from 19,000 Finnish mothers with schizophrenia between 1960 and 1979 were followed up
• their adoptive parents were assessed for child-rearing style
• children were followed up
• their adoptive parents were assessed for child-rearing style and the rates of schizophrenia were compared to those in a control group of adopters without any genetic risk
• a child-rearing style characterised by high levels of criticism and conflict and low levels of empathy was implicated in the development of schizophrenia but only for the children with high genetic risk but not in he control group
• 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 very streng direct support for the importance of adopting an interactions approach to schizophrenia, including hanging on to the idea that poor parenting is a possible source of stress

Question 8

How is the fact that the original diathesis-stress model is over-simple a weakness of the interactionist approach?

Answer 8

• the classic model of a single schizogene and schizophrenic parenting style as the major source of stress is now known to be very over-simple
• multiple genes increase vulnerability to schizophrenia, each having a small effect on its own; there is no single schizogene
• also stress can come in many forms, including but not limited to dysfunctional parenting
• therefore vulnerability and stress do not have one single source
• in fact it is now believed that vulnerability can be the result of early trauma as well as genetic make-up and that stress can come in many forms including biological
• in one recent study by Houston et al childhood sexual trauma emerged as a vulnerability factor whilst cannabis use was a trigger
• this shows that the old idea of diathesis as biological and stress as psychological has turned out to be overly simple
• this is a problem for the old idea of diathesis-stress but not for newer models

Question 9

How does support for the effectiveness of combinations of treatments a strength of the interactions approach?

Answer 9

• there is support for the usefulness of adopting an interactionist approach from studies comparing the effectiveness of combinations of biological treatments alone
• as Turkington et al point out it is not really possible to use combination treatments without adopting an interactions approach
• studies show an advantage to using combinations of treatments for schizophrenia
• for example in one study by Terrier et al 315 patients were randomly allocated to a medication + CBT group, medication + supportive counselling or a control group
• patients in the two combination groups showed lower symptom levels than those in the control group (medication only) although there was no difference in rates of hospital readmission
• studies like this show hat there is a clear practical advantage to adopting an interactionist approach in the form of superior treatment outcomes and therefore highlight the importance of taking an interactions approach

Question 10

What is the modern understanding of stress?

Answer 10

• in the original diathesis-stress model of schizophrenia, stress was seen as psychological; in nature, in particular related to parenting
• although psychological stress, including that resulting from parenting may still be considered important, a modern definition of stress in relation to the diathesis-stress model includes anything that risks triggering an episode of schizophrenia has concerned cannabis use
• in terms of the diathesis-stress model cannabis is a stressor because it increases the risk of schizophrenia by up to seven times according to dose
• this is probably because cannabis interferes with the dopamine system
• however most people do not develop schizophrenia after smoking cannabis so it seems there must also be one or more vulnerability factors

Question 11

How is the fact that we don’t know exactly how diathesis and stress works a weakness of schizophrenia?

Answer 11

• there is strong evidence to suggest that some sort of underlying vulnerability coupled with stress can lead to schizophrenia
• we also have well informed suggestions for how vulnerabilities and stress might lead to symptoms
• however, we do not yet fully understand the mechanisms by which the symptoms of schizophrenia appear and how both vulnerability and stress produce them

Question 12

What was tainaris study?

Answer 12

• studied 304 adoptees
• 14 has developed schizophrenia over the course of the study
• 11 of these were from a high risk group and 3 were from the low risk group
• those reared in a healthy adoptive family however appeared to have a productive effect even for those at high genetic risk of schizophrenia
• high genetic risk adoptees reared in families with low OPAS ratings were significantly less likely to have developed schizophrenia than high genetic risk adoptees reared in families with high OPAS ratings
• psychiatrists involved were blind to the biological mothers condition