Also important are illness and treatment perceptions, which have been shown to
be associated with the onset of chronic fatigue following infectious diseases.
For example, a study by Candy and colleagues found perceptions about
the expected illness duration and long-term impact to be predictive of poorer
outcomes up to six-months after onset of Infectious Mononucleosis (IM)
(Candy et al., 2003). A later, larger study of predictors of CFS following IM found that
negative illness perceptions -including believing the condition to be serious and
distressing, that it would last a long time, and was incontrollable- predicted a
subsequent diagnosis. Of the cognitive and behavioural responses to symptoms
examined, ‘all or nothing’ behaviour, defined as bursts of activity with a need to
rest afterwards, also predicted a subsequent diagnosis, and in fact was the
strongest predictor (Moss-Morris et al., 2011). Moreover, in a study comparing
patients already diagnosed with CFS with those suffering from rheumatoid
arthritis- a more clearly defined condition with overlapping symptoms- CFS
patients held more negative illness perceptions. Physical disability was
comparable across the two groups. However, CFS patients reported greater
problems with social functioning and limitations to everyday activities as
a result of their symptoms (Moss-Morris & Chalder, 2003).
Illness or symptom attributions, related to the factors which patients or
individuals feel have caused their condition or made it worse, may also be
relevant. There are three overarching categories: somatic (i.e. a physical
abnormality), psychological (e.g. emotional upset) and normalising (external
events, e.g. a change in environment or behaviour) (Moss-Morris, 2005). A
study of PVFS found that tendency to attribute symptoms to somatic factors
was the strongest risk factor for subsequent chronic fatigue (Cope et al., 1994).
CFS patients have been shown to be less likely to make psychological
attributions, and to make similar physical attributions to Multiple Sclerosis
patients (Dendy et al., 2001). A community study of fatigued individuals found
that those attributing their fatigue to social factors were more ‘protected’ than
those making biological attributions from later fatigue and disability (Chalder et
al., 1996). Findings concerning the effect on outcome following treatment for
CFS have been mixed. One study in primary carefound that physical illness
attributions predicted a worse outcome (Chalder et al., 2003). Studies of tertiary
care services, however, found no link (Deale et al., 1998; Kempke et al., 2010).
Another concept that has been examined in CFS patients is ‘willingness’. In this
case, ‘willingness’ can be defined as the appreciation that avoidance and
control of symptoms are not always possible. A lack of ‘willingness’ indicates a
lack of acceptance of fatigue, which has been linked to increased disability.
However, it has also been shown to be modifiable following cognitive
behavioural therapy interventions(Brooks et al., 2011).
In this thesis, I will explore the relevance of illness perceptions and cognitive
and behavioural responses to fatigue to the persistence of fatigue following
another immune trigger not yet studied in this context. Specifically, in patients
who have been treated with IFN-α, to be described in the next section. I will also
compare attributions made, and levels of acceptance of fatigue in the IFN-α
treated patients, healthy volunteers and patients with CFS.
