Interactionist Approach

Interactionist Explanation:

The Diathesis-stress model sees schizophrenia as the result of an interaction between biological (diathesis) and environmental (stress) influences (also known as the bio-social approach).

Meehl’s (1962) Old Diathesis-Stress Model

Meehl believed that schizophrenia is the result of a single schizogene, combined with chronic stress, in particular the schizophrenic mother. Meehl believed that if a person did not have the schizogene, then no amount of stress would lead to schizophrenia. There has to be the combination of nature and nurture.

The Modern Diathesis-Stress Model

Meehl’s diathesis stress model is far too simplistic. It is now clear that schizophrenia is polygenetic. This means that there are multiple genes which work in combination in influencing schizophrenia. However, the modern approach goes beyond genetics, it also looks at trauma to the developing brain. Furthermore, it is clear that there is not just one type of stress that interacts with schizophrenia. Although issues in the family may still be considered influential, the modern definition of stress includes anything that risks triggering schizophrenia.

Read et al. (2001) proposed a neurodevelopmental model in which early trauma such as child abuse can alter the developing brain and make an individual much more vulnerable to later stress.

Much of the recent research into factors triggering an episode of schizophrenia has concerned cannabis use. Cannabis increases the risk of schizophrenia by up to seven times. However, this is when cannabis is smoked in high doses, and in people with a pre-existing, genetic vulnerability to schizophrenia. This may act as a particular risk factor, because cannabis interferes with the dopamine system.

Key Study: Tienari et al (2004)

Procedure – Hospital records were reviewed for nearly 20,000 women admitted to Finish psychiatric hospitals between 1960 and 1979, identifying those that had been diagnosed at least once with schizophrenia. 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 an interval of 12 yrs, with a follow up after 21 yrs. Psychiatrists also assessed family functioning in the adoptive families using a scale – the Oulu Family Rating Scale (OPAS scale). It measures families on various aspects of functioning such as parent-offspring conflict, lack of empathy and insecurity. The interviewing psychiatrists were kept blind as to whether the biological mother was schizophrenic or not.

Findings – of the 303 adoptees, 14 developed schizophrenia over the course of the study. 11 of these were from the high risk group, and 3 from the low risk group. However, being reared in a ‘healthy’ adoptive family appeared to have a protective effect for those that had a high genetic risk. In addition, family stress was a significant predictor of the development of schizophrenia in the adoptees that had a high risk of schizophrenia. This is because they found that a child rearing style with high levels of criticism and conflict and low levels of empathy appeared to be associated with developing schizophrenia, but only for the children with high genetic risk.

Evaluation

Strengths:

Holistic/Validity – The fact that this explanation considers both nature and nurture enables the explanation to be more accurate. This is because, nature and nurture can not be separated, and therefore, they must both play some role in schizophrenia. By looking at it holistically by considering a number of combinations in genetics/biology and external influences, it helps to build a more realistic explanation.
Application/Usefulness – There is support for the usefulness of adopting an interactionist approach from studies comparing the effectiveness of combinations of biological and psychological treatments vs biological treatments alone. For example, family therapies or CBT, tend to use drugs to improve the issues that certain genes can create, but also the stressors in the environment by supporting the family. Studies like this show that there is a clear practical advantage to adopting an interactionist approach in the form of superior treatment outcomes and therefore highlight the importance of an interactionist approach. Research by Tarrier et al. (2000) found that people with schizophrenia receiving 20 sessions of CBT in 10 weeks, coupled with drug therapy, followed by four booster sessions during the next year, had a better reduction in symptoms than sufferers receiving drug therapy alone.
Research to support – Research above by Tienari (2004) supports the diathesis-stress model in explaining schizophrenia, helping to strengthen the credibility of the explanation.

Weaknesses:

Individual differences – within any explanation, it tends to take a nomothetic approach which does not consider individual differences. Not everyone who has a certain combination of genes and stressors will develop schizophrenia. All research simply suggests an increased vulnerability. Therefore, may not be a complete explanation for all individuals with schizophrenia. In the research by Tienari, not all participants who had a genetic vulnerability and a negative family environment, developed schizophrenia. Maybe there are dispositional explanations which have not been considered by the interactionist explanation.
Longitudinal research – Tienari et al (2004) acknowledged that the study failed to reflect developmental changes in family functioning over time, as they only completed the OPAS scale once. They also acknowledge that observing reciprocal interactions between the adoptive family and the adoptees makes it impossible to determine how much of the stress observed is assigned to the family and how much is actually caused by the adoptee him or herself.

Interactionist Treatment:

The interactionist treatment utilizes a combination of biological and psychological treatments. Typically, the patient will start with a drug treatment, and then participate in CBT alongside the drug treatment.

Atypical anti-psychotics such as Clozapine works by blocking post synaptic dopamine receptors and post synaptic serotonin receptors. It is theorised that people with schizophrenia have too much dopamine and serotonin, so by blocking the receptors, it reduces the amount they are received and may help to bring serotonin and dopamine to a normal level.

Cognitive behavioural therapy assumes that schizophrenia is the result of dysfunctional thought processes. For example faulty cognitions such as delusions are identified with CBT and ultimately changed. The therapists role is to challenge irrational beliefs, this could be by logically disputing the reality of the delusions and helping to develop alternatives. CBT can take between 5 and 20 sessions.

Identify: ABC (DE) model by Ellis is used to understand the source of the faulty cognition, and provide a process to cognitively restructure irrational beliefs (delusions). The therapist will firstly use the ABC model to identify the irrational beliefs. See the example below:

A – Activating event – Drug treatment causes side effects

B- Beliefs – Hospital staff are trying to kill them

C-Consequences – Refusing treatment

Educate: Once the irrational belief is identified, the irrational belief is challenged by the therapist through a process called Disputing (we have covered this before in the cognitive treatments for depression).

D – Disputing irrational beliefs

Logical Dispute – (does it make sense?) Why would the staff want to kill you? Could there be other reasons for having side effects to the drugs? This line of questioning would help the patient to see that the staff have no reason to kill them.

Empirical Dispute – Within a CBT session the therapist will encourage the use of Reality Testing in order to challenge the irrational beliefs. For example, the therapist may ask the patient to think of examples when the staff have protected you? Maybe focusing on the idea that they are still alive. This is an example of empirical dispute, as the therapist is encouraging the patient to look for evidence.

This line of questioning can be carried out without causing distress, provided there is an atmosphere of trust between the patient and the therapist, who remains empathetic and non-judgmental.

E – restructured belief (Effect) – This is the outcome in response to the cognitive therapy. The patient develops a new belief that is a more accurate reflection of reality – The drugs are necessary for me to get better.

Evaluation:

There is research to support: the modernised version of the diathesis stress model. Tienari et al. who investigated the combination of genetic vulnerability and parenting style in children adopted from Finnish mothers with schizophrenia. The adoptive parents were assessed for child-rearing style and the rates of schizophrenia were compared to those in a control group of adoptees without any genetic risk. They found that a child rearing style with high levels of criticism and conflict and low levels of empathy appeared to be associated with developing schizophrenia but only for the children with high genetic risk. This supports the interactionist explanation that both genetic vulnerability and family-related stress are important in the development of schizophrenia. This provides a more credible explanation because nature and nurture cannot be separated. By considering both factors, it is likely to provide a more accurate explanation of schizophrenia.
Alternative explanation: However, not all children developed schizophrenia when faced with a genetic vulnerability, and negative child rearing. This suggests that other factors need to be considered. For example, the influence of dispositional factors such as personality types may also play a role in explaining schizophrenia.
Research to support: It is also accepted that a range of factors can cause the predisposition or diathesis, and these include physical and psychological trauma that effect the developing brain. In addition, the range of stressors that can trigger schizophrenia has been widened to include cannabis use, as it appears to increase the risk of developing schizophrenia by up to 7 times. The fact that there is evidence which suggests a connection between many external factors means that researchers need to further investigate the potential for other combining factors. This allows people to make informed choices about drug use, especially if they have a genetic predisposition.
Usefulness/effectiveness: There is research to support the effectiveness of an interactionist treatment. For example, Tarrier et al. randomly allocated patients to either a medication plus CBT group, a medication plus supportive counselling group and a control group who just took medication. They found that patients in the two combination groups showed lower levels of symptoms than those in the control group. This is a clear benefit of the interactionist approach because it shows that it targets more symptoms when using a combination approach and this will help to improve the quality of life for the patient.
Usefulness/effectiveness: In addition, by taking a combination approach, you can avoid issues such as the treatment causation fallacy. This is the assumption, that when using one treatment such as drugs, if symptoms are reduced, it is assumed that the cause is biological. The same applies to CBT, because if symptoms are reduced, it is assumed to have a cognitive cause. However, it might be too simplistic to make this assumption. By using an interactionist treatment, it ensures all bases are covered by targeting cognition, behaviour and biology, which will hopefully lead to a more successful treatment.
There is research to support the effectiveness of an interactionist treatment. For example, Tarrier et al. randomly allocated patients to either a medication plus CBT group, a medication plus supportive counselling group and a control group who just took medication. They found that patients in the two combination groups showed lower levels of symptoms than those in the control group. This is a clear benefit of the interactionist approach because it shows that it targets more symptoms when using a combination approach and this will help to improve the quality of life for the patient. In addition, by taking a combination approach, you can avoid issues such as the treatment causation fallacy. This is the assumption, that when using one treatment such as drugs, if symptoms are reduced, it is assumed that the cause is biological. The same applies to CBT, because if symptoms are reduced, it is assumed to have a cognitive cause. However, it might be too simplistic to make this assumption. By using an interactionist treatment, it ensures all bases are covered by targeting cognition, behaviour and biology, which will hopefully lead to a more successful treatment.