An Interactionist Approach

Question 1

What is the interactionist approach?

Answer 1

The diathesis stress model

Question 2

What is the diathesis-stress model?

Answer 2

Explains mental disorders as the result of an interaction between biological (the diathesis) and environmental (stress) influences.

Question 3

What do family study’s suggest?

Answer 3

People have varying levels of inherited genetic vulnerability to schizophrenia, from very low to very high.

Question 4

What’s the diathesis?

Answer 4

The genetic component in terms of vulnerability

Question 5

What supports the diathesis?

Answer 5

Findings that the identical twin of a person with schizophrenia is at greater risk of developing schizophrenia than a sibling of fraternal twin, and that adoptive relatives do not share the increased risk of biological relatives (Tienari, 2004).

Question 6

What supports the stress?

Answer 6

Not 100% concordance rates, so must be environmental factors as well.

Question 7

What does the stress suggest?

Answer 7

Stressful life events can trigger schizophrenia and can take a variety of forms such as childhood trauma or the stresses associated with living in a highly urbanised environment.

Question 8

What did Varese (2012) find? (Stress)

Answer 8

That children who experienced severe trauma before the age of 16 were 3X as likely to develop schizophrenia in later life compared to the general population.

There was a relationship between the level of trauma and the likelihood of developing schizophrenia, with those severely traumatised as children being at greater risk.

Question 9

What did Vassos (2012) find? (Stress)

Answer 9

A meta-analysis found that the risk for schizophrenia in the most urban environments was estimated to be 2.37X higher than in the most rural environments.

Question 10

How are urbanisation and schizophrenia linked?

Answer 10

It is not clear.

Possible that the more adverse living conditions of densely populated urban areas, but only a tiny minority of these will develop schizophrenia.

Question 11

How does the diathesis-stress model play a part in schizophrenia?

Answer 11

Minor stressors may lead to the onset of the disorder for an individual who is highly vulnerable.

Or a major stressful event might cause a similar reaction in a person low in vulnerability.

Question 12

What’s the key study?

Answer 12

Tienari - 2004

Question 13

What was the procedure for Tienari’s study?

Answer 13

Hospital records were reviewed for nearly 20,000 women admitted to Finnish psychiatric hospitals between 1960 and 1979, identifying those who had been diagnosed at least once with S or paranoid psychosis.

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 (high-risk group) was them matched with a sample of 158 adoptees without this genetic risk (low-risk group).

Both groups were independently assessed after a median interval of 12 years, with a follow-up after 21 years.

Psychiatrists also assessed family functioning in the adoptive families using the OPAS. This scale 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 the status of the biological mothers.

Question 14

What were the findings for Tienari’s study?

Answer 14

Of the 303 adoptees, 14 had developed S over the course of the study.

Of these 14, 11 were from the high-risk group and 3 were from the low-risk group.

However, being reared in a ‘healthy’ adoptive family appeared to have a protective effect even for those at high genetic risk.

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.

In adoptees at high genetic risk of S, but not in those at low genetic risk, adoptive-family stress was a significant predictor of the development of S.

Question 15

What are the evaluative points?

Answer 15

Diathesis may not be exclusively genetic
Urban environments are not necessarily more stressful
Difficulties in determining casual stress
Limitations of the Tienari study
Implications for treatment.

Question 16

What is meant by diathesis may not be exclusively genetic?

Answer 16

Diathesis stress models emphasise vulnerability due to genetic influences alone, which are assumed to result in an increased risk for schizophrenia.

However, this increased risk can also result from brain damage caused by obstetric complications at birth.

Verdoux estimated the risk of developing schizophrenia later in life after obstetric complications is 4x greater than for those who experience no such complications.

However, researchers claim that birth complications are caused by an already compromised foetus (Weinberger)

Question 17

What is meant by urban environments are not necessarily more stressful?

Answer 17

Not all research has agreed with the finding that living in densely populated urban environments was a significant stress factor for schizophrenia.

E.g. Paykel (2000) although finding evidence of urban-rural differences, showed that these differences disappeared after adjusting for the socio-economic differences for the two groups.

This suggests that, although social adversity may well be a significant trigger for schizophrenia, the claim that social adversity and urbanisation are synonymous is likely to be an oversimplification.

Question 18

What is meant by difficulties in determining causal stress?

Answer 18

It is possible that stressors earlier in life can also influence how people respond to later stressful events and increase their future susceptibility to the disorder.

Maladaptive methods of coping with stress in childhood means that the individual fails to develop effective coping skills, which in turn compromises their resilience and increases vulnerability to schizophrenia.

Ineffective coping skills may, therefore, make life generally more stressful for the individual and so trigger mental illness.

Question 19

What is meant by implications for treatment?

Answer 19

If the onset of schizophrenia is a result of the additive effect of genetic vulnerability and environmental stress, this has implications for its treatment.

Found that women infected with cytomegalovirus during pregnancy were more likely to have a child who developed schizophrenia, but only if both mother and child carried a particular gene defect.

This suggests that antiviral medicine during pregnancy may prevent the onset of schizophrenia in the offspring of women known to have this gene defect.