ME/CVS-patiŽnten met fibromyalgie en patiŽnten met een groot aantal non-specifieke klachten
maken aanzienlijk minder kans op herstel volgens een studie van
Natelson en kollega's.
De hypothese van
Wessely en geloofsgenoten dat
ME/CVS, prikkelbaar darm-syndroom, fibromyalgie etc.
verschillende kanten van ťťn en dezelfde ("psychosomatische") medaille zijn,
wordt weersproken door het feit dat de diagnose ME/CVS en fibromyalgie onafhankelijk van elkaar invloed uitoefenen op het eindresultaat:
de mate van herstel (van het fysiek funktioneren).
Enkele citaten uit het uitgebreide studierapport:
Case-control studies have shown that
perceived loss of function in CFS equals or exceeds
that observed in multiple sclerosis, congestive heart failure, diabetes, mononucleosis, and acute myocardial infarction
(Buchwald et al., 1996; Komaroff et al., 1996).
Improvers were defined as those with a positive illness trajectory in PF (slope 0),
whereas Non- Improvers had a negative or flat trajectory (slope 0)
over 2 1/2 years of study observation.
To summarize, the aims of the present study were to
(1) establish illness trajectories for CFS Improvers and Non-Improvers based on changes in perceived physical functioning;
(2) compare Improvers and Non-Improvers on pre-existing demographic and illness-related factors;
(3) determine whether an initial diagnosis of FM predicts CFS nonimprovement at 2 1/2 year follow-up; and
(4) determine whether the effect of FM on CFS outcome is mediated by somatization in the form of multiple nonspecific symptoms.
This subscale [Symptom Checklist-90 Somatization Scale , FT]
contains a list of 12 nonspecific medical complaints often encountered in primary care (Derogatis et al., 1973).
The scale is widely used to assess symptom reporting and
has well established psychometric properties (Derogatis et al., 1976; Lipman et al., 1979).
The patients task is to rate the degree of discomfort caused by each symptom
during the preceding 2 weeks using a numerical scale ranging from 0 (no discomfort) to 4 (a lot of discomfort).
In the present study, we defined
a somatization score for each participant (at each time point)
as the mean rating per item (sum of symptom ratings divided by number of items rated).
We chose to identify Somatizers on a purely empirical basis
as those with baseline (initial) scores above the median on the Symptom Checklist-90 Somatization scale.
Instead, we focused on a single dimension of illness outcome,
namely perceived change in physical functioning.
After controlling for FM,
women with CFS who were classified as Somatizers were
3.33 times (p < 0.05) more likely to experience a negative trajectory
when assessed 2 1/2 years later.
Similarly, after controlling for nonspecific symptoms,
females with CFS who had concurrent FM were
3.23 times (p < 0.05) more likely to follow a downward course.
It has been suggested by some that
somatization and FM represent manifestations of the same underlying illness (Fink et al., 2007; McBeth et al., 2001).
Consistent with this suggestion we found that 66% of patients with FM
compared with just 37% of patients without FM were classified as Somatizers in the present study, chi square . 7.69, p < 0.01.
If the single syndrome hypothesis is correct,
nonspecific symptoms should mediate the effects of FM and thereby attenuate the association between FM and CFS outcome.
We tested this prediction by simultaneously inserting both variables into the regression equation (Model IV).
Neither the effects of Somatization nor the effects of FM on illness trajectory
were attenuated (compared with the risk of either one considered separately)
suggesting that each acted independently.
Illness trajectories in the chronic fatigue syndrome: a longitudinal study of improvers versus non-improvers.
J Nerv Ment Dis. 2010 Jul;198(7):486-93. doi: 10.1097/NMD.0b013e3181e4ce0b.
Ciccone DS, Chandler HK, Natelson BH.
The natural progression of chronic fatigue syndrome (CFS) in adults is not well established.
The aims of this longitudinal study were to
- compare CFS Improvers and Non-Improvers;
- determine whether an initial diagnosis of fibromyalgia (FM) was associated with CFS nonimprovement; and
- determine whether this effect could be explained by the presence of nonspecific physical symptoms.
Consecutive referrals to a tertiary clinic that satisfied case criteria for CFS
were invited to enroll in a longitudinal study.
After an initial on-site physical examination and psychiatric interview,
a total of 94 female care-seekers completed biannual telephone surveys,
including the Short Form-36 physical functioning (PF) scale,
over a period of 2 1/2 years.
very few differences between Improvers and Non-Improvers at baseline
but at final assessment
less disability, less fatigue, lower levels of pain, fewer symptoms of depressed mood,
and fewer nonspecific physical complaints.
Participants with FM at baseline
were 3.23 times (p < 0.05)
more likely to become Non-Improvers than those without FM.
Participants identified initially as Somatizers
were 3.33 times (p < 0.05)
more likely to become Non- Improvers.
Patients with CFS who bear the added burden of FM
are at greater risk of a negative outcome
than patients with CFS alone.
This effect could not be explained by the presence of multiple, nonspecific symptoms.
Chronic fatigue syndrome, fibromyalgia, symptom reporting, longitudinal, comorbidity.