Interactionist Approach to Schizophrenia

Question 1

The interactionist approach

Answer 1

• acknowledges there are biological, psychological and societal factors in the development of schizophrenia
• Biological: genetic vulnerability and neurochemical and neurological abnormality
• Psychological: stress resulting from life events and daily hassles, including poor quality interactions in the family

Question 2

Meehl’s Model (1962)

Answer 2

• believed diathesis was entirely genetic, the result of a single ‘schizogene’
• this led to the development of a biologically based schizotypic personality: one characteristic is sensitivity to stress
• according to Meehl, if a person doesn’t have the schizogene then no amount of stress would lead to schizophrenia
• however, in carriers of the gene, chronic stress through childhood and adolescence, particularly a schizophrenic mother could result in schizophrenia

Question 3

Modern Understanding of Diathesis

Answer 3

• it is now clear that many genes increase genetic vulnerability. There is no single ‘Schizogene’

• modern views of diathesis also include a range of factors beyond the genetic, including psychological trauma- trauma becomes the diathesis rather than the stressor

• Read et al. (2001) proposed a neurodevelopment model in which early development in which early trauma alters the developing brain. E.g. the hypothalamic-pituitary-adrenal system (HPA) becomes over-active and the person is more vulnerable to later stress

• originally stress was seen as psychological in nature, in particular related to parenting
• psychological stress is still seen as important, a modern definition of stress includes anything that risks triggering schizophrenia, e.g. cannabis
• cannabis is a stressor because it increases the risk of schizophrenia 7* as it interferes with the dopamine system
• however most don’t develop schizophrenia after smoking cannabis so there must be other vulnerability factors (Houston et al. 2008)

Question 4

Interactionist Treatment

Answer 4

• this approach acknowledges both biological and psychological factors and is compatible with both types of treatment
• model combines antipsychotics with psychological therapies such as CBT
• standard practice in GB to combine the two and is unusual to treat using psychological therapies alone

Question 5

(Evaluations of Diathesis) Tienari 2004

Answer 5

• investigated combination of genetic vulnerability and parenting style (the trigger). Children adopted from 19,000 Finnish mothers with schizophrenia between 1960-1979 followed up

• adoptive parents assessed for child-rearing style and rates of schizophrenia were compared to those in a control group of adoptees without any genetic risk

• a child rearing style of 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 the control group

• this suggests that both genetic vulnerability and family stress are important in development of schizophrenia- genetically vulnerable children are more sensitive to parenting behaviour

Question 6

(Evaluations of Diathesis) Support for combinations of treatments

Answer 6

Tarrier (2004)

• 315 patients were randomly allocated to a medication and CBT group, medication and supportive counselling or a control group

• patients in the two combination groups showed lower symptom levels than control, although there were no difference in rates of hospital readmission

• this and other studies show there is clear advantage to adopting an interactionist approach

Question 7

(Evaluations of diathesis) The original diathesis-stress model is over simplistic

Answer 7

• idea of a single schizogene and schizophrenic parenting style as the major source of stress is oversimple

• multiple genes increase vulnerability, there is no single gene

• stress can also come in many forms not just dysfunctional parenting

• now believed vulnerability can be caused by early trauma as well as genetic make-up, and stress can come in many forms including biological

• Houston (2008) childhood sexual trauma emerged as a vulnerability factor whilst cannabis was a trigger. This shows the old idea of diathesis as biological and stress as psychological is over-simple. This a problem for the old idea of diathesis-stress but not for newer models

Question 8

(Evaluation of diathesis) We don’t know exactly how diathesis and stress work

Answer 8

• strong evidence to suggest some sort of underlying vulnerability coupled with stress can lead to schizophrenia

• 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