emotions and thoughts.. .’. The control group is asked to write about more superficial
topics such as how they spend their time. This intervention has been used with a
range of people including adults, children, students, patients and maximum security
prisoners and survivors of the holocaust who disclose a range of traumatic experi-
ences including relationship break-ups, deaths and abuse. The writing paradigm has
been shown to impact upon a range of outcome measures. Some research has shown
a reduction in subsequent visits to the doctor (e.g. Greenberg and Stone 1992; Pen-
nebaker and Beall 1986), re-employment following job loss (e.g. Spera et al. 1994),
absenteeism from work (Francis and Pennebaker 1992), self reported physical symp-
toms (Greenberg and Stone 1992; Petrie et al. 1995) and changes in negative mood
(Petrie et al. 1995). In terms of PNI, emotional expression through writing has also
been shown to effect the immune system. For example, it has resulted in changes in T
helper cell responses (Pennebaker et al. 1988; Petrie et al. 1998), Natural Killer cell
activity (Futterman et al. 1992; Christensen et al. 1996) and CD4 (T lymphocyte)
levels (Booth et al. 1997). Therefore this simple intervention provides support for the
PNI model suggesting a link between an individual’s psychological state and their
immune system. However, as with all associations research indicates that the impact
of emotional expression might vary according to aspects of the task and aspects of the
individual.
Aspects of the task
Writing versus talking: Some research has compared the effectiveness of writing
versus talking either into a tape recorder or to a therapist (e.g. Donnelly and Murray
1991; Esterling et al. 1994). The results showed that both writing and talking about
emotional topics were more effective than writing about superficial topics.
Type of topic: Some research has shown that changes in outcome only occur after
writing about particularly traumatic experiences (e.g. Greenberg and Stone 1992).
Others have found that it is the relevance of the topic to the outcome variable which
is important. For example, Pennebaker and Beall (1986) found that writing about the
experience of coming to college had a greater impact upon college grades than writing
about ‘irrelevant’ traumatic experiences.
Amount of writing: Research using the writing paradigm has varied the stipulated
time of writing both in terms of the length of sessions (from 15 to 30 minutes) and the
spread of sessions (over a few days to over a month). Smyth (1996) carried out a meta
analysis and concluded that writing over a longer period might be the most effective
approach.
Aspects of the individual
Demographics: Pennebaker (1997) concludes that the effectiveness of emotional
expression does not seem to vary according to age, level of education, language or culture.
STRESS AND ILLNESS 263