The interactionist approach to schizophrenia Flashcards
The interactionist approach
The interactionist approach acknowledges that there are biological, psychological and social factors in the development of schizophrenia.
Biological factors – genetic vulnerability, neurochemical and neurological abnormality
Psychological factors – stress resulting from life events and daily hassles
Social factors – poor quality interactions in the family
The diathesis-stress model
The diathesis-stress model is one way to present an interactionist approach. The diathesis-stress model says that both a vulnerability to schizophrenia and a stress-trigger are necessary in order to develop the disorder.
One or more underlying factors make a person vulnerable to developing schizophrenia but the onset of the condition is triggered by stress.
diathesis
vulnerability
stress
negative experience
Meehl’s model
In the original diathesis-stress model diathesis was entirely genetic, the result of a single schizogene. 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 genes, chronic stress through childhood and adolescence, and presence of a schizophrenogenic mother could result in the development of the disorder.
Modern understanding of diathesis
Our changing of diathesis has changed as it is now clear that many genes appear to increase genetic vulnerability, there is no singular schizogene. Modern views of diathesis also include a range of factors beyond genetic, including psychological trauma. Read et al (2001) proposed a neurodevelopmental model in which early trauma alters the developing brain. Early and severe enough trauma, can seriously affect many aspects of brain development. For example, the hypothalamic-pituitary-adrenal (HPA) system can become overactive, making a person more vulnerable to later stress.
Modern understanding of stress
In the original diathesis-stress model of schizophrenia, stress was seen as psychological in nature. Although psychological stress may still be considered important, a modern definition of stress includes anything that risks triggering schizophrenia. Much of the recent research into factors 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 7 times according to dose. This may be because cannabis interferes with the dopamine system. However most people do not develop schizophrenia after smoking cannabis presumably because they lack the requisite vulnerability factors.
Treatment according to the interactionist model
The interactionist model of schizophrenia acknowledges both biological and psychological factors in schizophrenia and is therefore compatible with both biological and psychological treatments. The model is associated with combining antipsychotic medication and psychological therapies, most commonly CBT.
In Britain it is increasingly common practice to treat people diagnosed with schizophrenia with a combination of antipsychotic drugs and CBT. Medication without an accompanying psychological treatment is more common in the US than in the UK.
Evaluation of Interactionist approach (brief)
:) supporting evidence, Tienari
:( original model = simplistic
:) combo of bio and psychological treatment
strengths of Interactionist approach
evidence supporting the role of both vulnerability and triggers. Tienari et al (2004) investigated the impact of both genetic vulnerability and a psychological trigger (dysfunctional parenting). The study followed 19,000 Finnish children whose biological mothers had been diagnosed with schizophrenia. In adulthood this high risk genetic group were compared to a control group of adoptees without a family history of schizophrenia. Adoptive parents had been assessed for child-rearing style and it was found that high levels of criticism, hostility and low levels of empathy were strongly associated with the development of schizophrenia, but only in the high genetic risk group. This shows that a combination of genetic vulnerability and family stress can lead to greatly increased risk of schizophrenia.
a further strength of the interactionist approach is the combination of biological and psychological treatments. A practical application has been the combination of drug treatment and psychological therapies. Studies show that combining treatments enhances their effectiveness. Tarrier et al (2004) randomly allocated 315 participants to medication + CBT, medication + counselling or control group (medication only). Participants in the two combination groups showed lower symptoms following the trial than the medication-only group. This means that there is a clear practical advantage to adopting an interactionist approach to schizophrenia in terms of superior treatment outcomes.
weakness of Interactionist approach
the original diathesis-stress model was overly simplistic. Multiple genes in multiple combinations influence diathesis not the single schizogene that was initially suggested. Stress also comes in many forms. Diathesis can also be influenced by psychological factors and stress can be biological as well as psychological. A study by 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 means that there are multiple factors affecting both diathesis and stress, supporting the modern understanding of both diathesis and stress.
