STRESS THEORY AND RESEARCH 53describe events, which are then rated by trained individuals. The most well-known
example of this is the Life Events and Difficulties Schedule (LEDS) developed by
Brown and Harris (1978). This was used in an important study of life events, social
support and depression, which is described in more detail in Chapter 5 (Brown and
Harris, 1978).
Over the past 50 years researchers have studied the relationship between life events
and disease. Yet there is still controversy concerning whether major life events do cause
disease. The early studies showed strong links but have been subject to criticism.
Literature on breast cancer provides a good example of how some well-publicized
studies find links between life events and cancer (e.g. Geyer, 1991; Chen et al., 1995)
but other research fails to support the findings (e.g. Greer and Morris, 1975; Protheroe
et al., 1999). Many studies have used what is known as a ‘limited prospective design’.
For example, Chen et al. (1995) studied 119 women who were referred for biopsies
for suspected breast cancer. They were interviewed and their experience of life events
was assessed before they received a definitive diagnosis. The researchers found that 19
out of 41 women who were subsequently diagnosed with cancer had experienced
threatening life events during the 5 years before diagnosis compared with 15 out of
the 78 controls. While isolated studies such as this often get media publicity and
strengthen public perceptions that there is a link, literature reviews and meta-analyses
of the overall associations tend to conclude that there is little evidence to link life events
and breast cancer incidence (e.g. Nielsen and Brønbæk, 2006), though it is still unclear
whether stress may affect progression of the disease.
Stressful life events may be more strongly linked to psychological outcomes.
Research into life events in extreme situations such as wars and natural disasters suggests
that exposure to such events is likely to lead to serious psychopathology (Dohrenwend,
2000). There is also convincing evidence that stressful life events are linked to an
increase in depression (Kessler, 1997; Mazure, 1998). However, it is clear that there
are considerable individual differences in people’s susceptibility. The idea that some
people are genetically more susceptible to stressors is known as the stress diathesis model
(the term ‘diathesis’ meaning a predisposition to illness). A number of studies have
suggested that some people are indeed more genetically vulnerable to stressful life
events than others (e.g. Kendler et al., 1995). Advances in genetics have now enabled
researchers to explore specific genes that may be associated with this susceptibility. For
example, Lessard and Holman (2014) provide evidence that long-term health impacts
of exposure to child abuse and stressful life events in adulthood are moderated by
hypothalamic–pituitary–adrenal axis polymorphism genotypes.
Overall, despite the many criticisms of life events research, it seems to be an
approach that is here to stay with the number of studies increasing dramatically decade
by decade (Dohrenwend, 2006). Furthermore, modifications in methodology have
helped to improve reliability and validity of measurement.
Transactional theory and the daily hassles and uplifts approach
One of the most influential critics of life events research was Richard Lazarus who
suggested that the focus on major life changes, which are comparatively rare, ignores
the fact that a great deal of stress stems from recurrent day-to-day problems or chronic
conditions, which he describes as daily hassles. He also suggested that many of the other