response. The fourth is when an inadequate stress response causes the body to release
extra, unnecessary hormones and other chemical messengers, which may be harmful
to health. As you can see, this approach deals primarily with the physiological changes
that accompany stress. Contemporary psychological approaches are considered in the
next section.
CONTEMPORARY PSYCHOLOGICAL APPROACHES TO STRESS
In parallel with the development of physiological explanations of the stress process,
psychologists have focused on stress as a predominantly psychological phenomenon
and produced definitions and theories which concentrate on the psychological
precursors and processes. The three approaches described in this section have all been
influential but approach the conceptualization and study of stress in different ways.
For each approach the evidence linking them to disease is considered.
Life events
The study of major life events is perhaps the earliest, as well as most enduring, approach
to measuring stressors. The idea that emotionally distressing events might be associated
with disease and particularly cancer goes back at least as far as the nineteenth century
where many anecdotal reports of links between negative events such as bereavement
and cancer can be found in the medical literature (LeShan, 1959). The first statistical
study of this association is attributed to Snow (1893) who studied 250 cancer patients
in London and found that in over 60 per cent of them there had been some problem
before the onset of the disease. Frequently this was the death of a close relative.
More formal measurement approaches to studying life events originated in the 1960s
when Holmes and Rahe (1967) published a checklist of life events called the Social
Readjustment Rating Scale, which is reproduced in Table 3.1. The idea of a change
being stressful and requiring adaptation is central to the approach. Thus life events were
changes rather than persistent states. Furthermore, they were objectively verifiable events.
In the initial research to establish this measure, Holmes and Rahe drew on their
clinical experience to list 43 events. A sample of 394 people were asked to rate these
for the degree of ‘social readjustment’ they required. Marriage was given an arbitrary
value (50 in the final scale) and they were asked to assign numeric values to all the
other events based on how much more (or less) adjustment the event required than
marriage. The sum of ratings for events that an individual experiences in the last year
is known as their life change unit (LCU) score. Holmes and Masuda (1974) described
an LCU score of over 150 in one year as a life crisis (150–199 is a mild crisis;
200–299 a moderate crisis; and over 300 a major crisis). They also reported an early
study, which indicated that life crises were linked to deterioration in health. For
example, 37 per cent of those whose scores indicated they had experienced a minor
crisis and 79 per cent of those with a major crisis, reported changes in health. Further
studies in the 1970s by Rahe and colleagues suggested that high LCU scores were
linked with heart disease (Rahe and Paasikivi, 1971; Theorell and Rahe, 1971).
However, as the methodology has improved and more longitudinal studies have been
conducted, results have tended to be less consistent.
50 STRESS AND HEALTH