The Interactionist Approach Flashcards
The Interactionist Approach.
- Acknowledges there are biological, psychological and societal factors in the development of SZ.
- Biological factors include genetic vulnerability, neurochemical and neurological abnormality. Psychological factors include stress, resulting from life events/daily hassles including poor quality interactions in the family.
- This means the ideal treatment for SZ would be a combination of antipsychotic drugs and psychological therapy.
- A schizophrenic episode is seen as being triggered or worsened when environmental stressors (stress) combine with a biological diathesis (vulnerability).
Meehl’s (1962) - the original diathesis-stress model.
- Diathesis is entirely genetic: the result of single schizogene, which led to a biologically based schizotypic personality - extremely sensitive to stress.
- According to Meehl, no amount of stress will lead to SZ if the gene is not present.
- However, chronic stress through childhood and adolescence (schizophrenogenic mother) in someone with the gene could lead to the development of the disorder - nature/nurture interact.
Limitation of interactionist approach - original version over-simplified.
P: A limitation is that the
original version of the diathesis-stress model is over-simplified.
E: Houston et al. (2008) found
that childhood sexual trauma
emerged as a vulnerability
factor whilst cannabis use was a trigger – therefore the old idea of diathesis being solely biological is overly simplified.
L: This is a problem for the old idea of diathesis-stress but not for the newer models.
Modern understanding: Diathesis.
- There’s no longer thought to be one single ‘schizogene’ - there are many genes which appear to increase vulnerability to the illness (Ripke et al, 2014)
- Factors beyond genetic e.g. psychological trauma (trauma affects the development of the brain and becomes the diathesis, rather than the stressor).
- Read et al (2001) proposed a neurodevelopmental model in which early trauma alters the developing brain. Early and severe enough trauma, such as child abuse, can seriously affect many aspects of brain development, making an individual more vulnerable to stress later on.
Modern understanding: Stress.
- In original diathesis-stress model of SZ, stress was seen as psychological in nature, particularly related to parenting.
- Modern definition of stress in relation to diathesis stress model includes anything that risks triggering SZ (Houston et al, 2008)
- Much of recent research into factors triggering an episode of SZ has concerned cannabis use.
- Cannabis is biological stressor because it increases the risk of SZ by up to 7x according to dose. This is because cannabis interferes with the dopamine system.
- However, most people do not develop SZ after smoking cannabis (only about 3% of users who consume a high dose from the age of 18-long term) so there must be one or more vulnerability factors.
- Research suggests high dosage cannabis users that do develop SZ usually suffer the illness due to other confounding variables such as child sexual abuse.
Pregnancy and birth complications - Cannon et al (2002)
- Found a positive correlation between birth complications and later vulnerability to developing SZ, with some indication of damage to hormone and neurotransmitter systems as well as immune system.
- Biological vulnerabilities interact with later stressors to that may trigger the disorder.
Pregnancy and birth complications - Murray (1996)
- Reported that children who were born after flu epidemics where their mothers had contracted the disease whilst pregnant (especially in second trimester) had an 88% increased chance of developing SZ than children born in the same time period whose mothers had not contracted flu.
- Exposure to the flu during the second trimester is suspected of causing defects in neural development, which leads to increased vulnerability to SZ due to brain damage which has a knock on effect on dopamine functioning.
Tienari et al (2004) - adoption study.
- Hospital records were reviewed for nearly 20,000 women admitted to Finnish psychiatric hospitals between 1960-79, identifying those that had been diagnosed at least once with SZ. The list was checked to find those mothers who had one or more of their offspring adopted away. The resulting sample of 145 adopted-away offspring (the high-risk group) was then matched with a sample of 158 adoptees without this genetic risk (low risk group).
- Both groups of adoptees were independently assessed after interval of 12 years, with follow up after 21 years. Psychiatrists also assessed family functioning in adoptive families using OPAS scale - measures families on various aspects of functioning e.g. parent offspring conflict, lack of empathy and insecurity. The interviewing psychiatrists were kept blind as to whether the biological mother was SZ or not.
- Of the 303 adoptees, 14 developed SZ over the course of the study. 11 of these were from high risk group and 3 from low risk group.
- However, being reared in ‘healthy’ adoptive family appeared to have defensive effect even for those that had high genetic risk.
Tienari et al (2004) - adoption study: Conclusion.
In adoptees at high risk of SZ, but not in those at low genetic risk, adoptive-family stress was a significant predictor of the development of SZ.
- Therefore, supporting the diathesis-stress model explanation for the onset of SZ being a combination of genetic vulnerability and stressors.
What research methods information can you draw from this study?
- The researcher were kept blind, this means that there were less risks of researcher bias and subjectivity.
- Longitudinal study allows you to see how a variable can affect people over time (strength) however influences may even factor in (also known as extraneous variables).
- Sample if Finnish mothers and adoptive families - child rearing styles may differ in other settings.
Interactionist treatment.
- Although effectiveness of treatments is dependent upon factors such as cost, relapse rates, degree of side effects and symptom reduction - researchers believe that a combination therapy should be employed simultaneously between antipsychotic drugs and psychological therapies such as CBT or family therapy.
- Generally, antipsychotics are given first so that first so that psychological treatments will then have a greater effect.
- Combination treatments are standard practise in Britain, however in the USA, biological therapies without accompanying psychological treatment is more common.
Strength of interactionist approach - comparing treatment combinations.
P: There is support for the
usefulness of adopting an
interactionist approach when
comparing treatment combinations.
E: Tarrier et al (2004) 315 patients were randomly allocated to a medication + CBT group, medication + supportive counselling or a control group. Patients in the combination groups showed lower symptom levels.
L: Studies like this show that there is a clear practical advantage to using a combination of biological and psychological treatments for SZ.
Limitation of interactionist approach - genes cannot determine outcomes.
P: Genes cannot determine outcomes on their own.
E: They need a particular
environment in which to express themselves. Therefore, genes that
predispose someone to have
increased vulnerability to SZ cannot cause the disorder on their own, instead they need particular stressors to be present to trigger the potential of the genes to bring about the disorder.
L: This is in-line with the
diathesis-stress model, therefore supporting it as an explanation for the onset of SZ.
Strength of interactionist approach - holistic view.
P: A strength of the updated
diathesis-stress model is that it provides a more holistic view of the onset of SZ.
E: Stressors that may contribute to a risk of developing SZ include biological, environmental,
psychological and social factors.
L: However, it is not known
precisely how these risks contribute to the diathesis-stress interaction for
any one person because specific causes of SZ may differ between individuals which creates an incomplete understanding of the
diathesis – stress model.
Research: stress - Walker (1997)
- Reported that SZ’s have higher levels of cortisol, related to severity of their symptoms.
- Stress related increases in cortisol levels heighten genetically influenced abnormalities in dopamine transmission that underpin vulnerability of SZ - triggering the onset of the disorder.
- Illustrating the interaction of biological and environmental factors in the development of SZ in line with diathesis-stress model.
- This research has been subject to some criticism - elevated cortisol levels may be an effect rather than a triggering factor of SZ. However, Walker (1997) reports that cortisol levels are higher immediately before the onset of SZ rather than during recovery - suggesting that elevated levels of cortisol does trigger SZ rather than being a consequence of it.
