Cumulative life stress in chronic fatigue syndrome - Nater et al ('11) (CDC research)

[Dolphin]

I've just read the following CDC study which involved, among other others, Bill Reeves:

Cumulative life stress in chronic fatigue syndrome.

Psychiatry Res. 2011 Sep 30;189(2):318-20. Epub 2011 Aug 15.

Nater UM, Maloney E, Heim C, Reeves WC.

Source
National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control & Prevention, Atlanta, GA, USA.

Abstract*

We studied the impact of cumulative life stress on CFS in a population-based study.

We found that exposure to stressors was significantly more common in persons with CFS compared to NF controls; those with CFS reported experiencing significantly higher levels of psychological distress.

Also, post-traumatic stress disorder was significantly more common in people with CFS.

These results not only corroborate findings from other studies but, importantly, extend those by: a) measuring a comprehensive spectrum of stress variables, b) for the first time presenting data on stress in a population-based study, thus minimizing the effects of recruitment bias, and c) diagnosing CFS by means of standardized, validated scales, thus allowing replication and extension of our findings.

Stress may be an important factor in the pathophysiology of CFS.

Consequently, future studies should provide a more detailed understanding of the processes that lead from stress to CFS using longitudinal designs.

Published by Elsevier Ireland Ltd.

PMID: 21840607 [PubMed - indexed for MEDLINE]

*I've given each sentence its own paragraph

 

[Dolphin]

It uses the Reeves et al. (2005) "empiric" criteria, although readers would have no real way of knowing from it alone (e.g. the 2005 paper isn't referenced at all).

Here's an extract which shows it isn't clear:

2.1. Study design

This study enrolled participants from the Wichita CFS Surveillance Study, conducted between 1997 and 2000 (for more information, please refer to Reyes et al., 2003) who also participated in a 2-day in-hospital case control study (conducted between 2002 and 2003). In brief, 43 subjects meeting criteria for CFS and 60 nonfatigued (NF) subjects were identified. CFS was diagnosed by criteria of the 1994 International Research Case Definition (Fukuda et al., 1994) as recommended by the International CFS study group (Reeves et al., 2003). To identify exclusionary medical conditions, a standardized medical history, review of current medications, standardized physical examination as well as routine blood and urine laboratory tests were performed as recommended by the International CFS Study Group.

The Reeves et al. (2005) paper shows there were 43 with that ("empiric") criteria: http://www.biomedcentral.com/content/pdf/1741-7015-3-19.pdf

This paper which explicitly says it used the Reeves et al. (2005) criteria:
--

Coping styles in people with chronic fatigue syndrome identified from the general population of Wichita, KS.
Nater UM, Wagner D, Solomon L, Jones JF, Unger ER, Papanicolaou DA, Reeves WC, Heim C.
J Psychosom Res. 2006 Jun;60(6):567-73.

--
Says there were 36 Female/7 male, average age 50.6, 3 non-white, all the same as the Nater et al. (2011) study.

The CDC (and others) need to be clear about what criteria are being used.

 

[Dolphin]

I generally think empiric criteria studies are virtually meaningless for what I suffer from. But for what it's worth, here are the details:

Finally, a multivariate logistic regression analysis was conducted to
determine which of the stress sub-scales found to be significant in the
prior analyses remained as significant independent predictors of CFS,
controlling for age, sex, and race. This analysis indicated that the
perceived stress summary score (P=0.042; odds ratio, OR: 1.18;
confidence interval, CI: 1.011.39) and Davidson trauma summary
score (P=0.033; odds ratio, OR: 1.09; confidence interval, CI: 1.01
1.18) were significantly associated with CFS, but the other stress
variables were not (classification hit/miss rate was 73.2% for CFS and
87.3% for NF).

This is what was measured by these scales:

We used the Perceived Stress Scale (PSS) (Cohen et al., 1983) to measure perceived
levels of stress. The PSS contains 14 items and is used to assess how unpredictable,
uncontrollable, and overloaded respondents considered their lives to be, using the last
week as a reference time frame. We computed a summary score (ranging from 0 to 40)
for each participant.

We used the Diagnostic Interview Schedule (DIS) (Robins et al., 1995) to identify a
current diagnosis of PTSD according to DSM-IV, and used the Davidson Trauma Scale
(DTS) (Davidson et al., 1997) to measure PTSD symptoms on a dimensional level. The
DTS is a self-report questionnaire used to record the frequency and severity of PTSD
symptoms. Davidson proposed that a threshold of 40 for a total symptom score was
highly likely to lead to a diagnosis of PTSD.

Regarding PTSD:

Further, using a possible PTSD
diagnosis based on a DTS score >40, significantly more persons with
PTSD were detected among the CFS group compared to controls.
However, when PTSD diagnosis was ascertained using the DIS, fewer
subjects were classified as having PTSD, and the differences between
the CFS and NF groups were no longer significant.

Using the threshold of >40, the percentages were 26.8% vs 9.3% i.e. even using this definition, 73.2% of "CFS" patients wouldn't have been classified as having possible PTSD using Davidson Trauma Scale.
Using Diagnostic Interview Schedule (DIS), the figures were only 9.3% vs 1.7% i.e. 90.7% of "CFS" patients wouldn't have been classified as having possible PTSD using Diagnostic Interview Schedule (DIS).

 

[Dolphin]

Figures taken *after* people ill

(Again, I don't find empiric criteria studies of much use but might as well see this through)

The figures that were significant generally relate to after people were ill.
However, people could be traumatised and/or under stress, not because of how they are themselves, but how others are reacting to them - the help (or otherwise) they are getting for governmental and non-governmental agencies, the health system/doctors, their family and friends, etc.

As the authors say themselves:

Due to the crosssectional nature of this and other examinations, the question remains
whether life events and experience of stress might actually be
triggering CFS or whether these variables occur more often as a
consequence of the illness.

 

[LaurelW]

I think they've got their chickens and eggs mixed up.

 

[Esther12]

So is this retrospective, and without a control group with a comparable illness?

I'd feel silly even asking that if it wasn't Nater. Thanks for the posts.

 

[Dolphin]

So is this retrospective, and without a control group with a comparable illness?

I'd feel silly even asking that if it wasn't Nater. Thanks for the posts.

Yes.
From 2011 paper

In brief, 43 subjects meeting criteria for CFS and 60 nonfatigued (NF) subjects were identified.

Nonfatigued means they weren't in the ISF group - one could be in the ISF group if one had fatigue or some of the other symptoms that might be part of CFS.

One can get more info from the Nater et al. (2006) and Reeves et al (2005) papers although it's probably not worth trying to follow all the details.
Here's a quote from 2006 paper:

We enrolled subjects who were identified in the Wichita
CFS Surveillance Study between 1997 and 2000 [2,19]. In
brief, the surveillance study used a random-digit-dialing telephone
survey to screen 56,146 adult residents, 18 to 69 years
of age, in Wichita, Sedgwick County, KS. A surveillance
cohort of 3528 adults who reported prolonged fatigue of at
least 1-month duration and 3634 nonfatigued persons
completed a detailed telephone interview. Eligible subjects
were clinically evaluated, and a subset of the cohort was
followed at 12, 24, and 36 months. All 70 people classified
as CFS at least once during the surveillance study were
invited to participate in the present in-hospital clinical study,
and 58 (83%) agreed to participate. Subjects with chronic
unexplained fatigue of at least 6 months duration, who did
not fulfill the criteria of the 1994 CFS Research Case
Definition due to insufficient symptoms of fatigue severity
(ISF group), were randomly selected from the surveillance
population, and 59 were enrolled. Non-ill (NI) controls were
selected from healthy subjects who never reported fatigue
during surveillance to match CFS cases based on sex, race/
ethnicity, age, and body mass index (NI group), and 55
participated. All subjects were admitted to a Wichita
hospital research unit for 2 days. During the hospital stay,
we reevaluated all subjects in terms of CFS symptoms as
well as exclusionary medical and psychiatric conditions.
The 43 subjects meeting criteria for current CFS at the time
of the clinic stay, 61 subjects with ISF, and 60 NI subjects
were included in this report. Demographic features are
summarized in Table 1.

 

[Dolphin]

Authors use study to plug CBT (and GET)

Final paragraph:

Numerous treatments have been applied to CFS patients with
various results. Experimental data support efficacy of graded exercise
training and cognitive behavioral therapy (CBT) (Rimes and Chalder,
2005). CBT strategies for CFS typically involve organizing activity and
rest cycles, initiating graded increases in activity, establishing a
consistent sleep regimen, attempting to restructure beliefs around
self, as well as disease attributions, and stress management. The latter
employs stress reducing strategies and improves coping behavior. It
seems critical to devote research resources to a detailed understanding
of the processes that lead from stress to CFS in order to improve
current treatment strategies.

The thing is that stress management isn't really a big part of CBT programs that are based on graded increases in activity.
And people can certainly be taught stress management without requiring them to have graded increases in activity.

 

[alex3619]

I am all for the teaching of stress management techniques. These are good, they can only help provided they are of a nature that the specific patient can implement them.

The vast majority of all the stress in my life is post-ME, either as a consequence of limitations imposed by ME, or as a consequence of how others have treated me because I have ME. I wonder if this whole paper could be more accurately summed up as "CFS causes stress"? They could post that on twitter and not have to go to all this rigmarole.

The CDC empiric definition is a joke. Any paper that uses it I don't take seriously. We don't know who they are studying, and neither do they, so we don't know who it applies to. The most that could be said is that a whole group of people with unknown or undiagnosed health problems involving fatigue are involved.

Bye, Alex

 

[Enid]

Presumably there is no definition for "cumulative life stress" except the psyches totting up "experiences" and making 2 + 2 = 5. QED.

 

[heapsreal]

We are stressed i guess, either trying to hold onto our jobs or going through the process of getting disability payments or even trying to survive off disability payments is going to be stressful. Maybe if they gave more assistance to people with cfs/me then this stressfullness would be alot lower. i think this stress happens with all chronic illnesses just like how they mention depression, its a symptom of a chronic illness, not the cause. they really are trying hard to make cfs/me a psychosomatic illness. Common Norway prove these buggers wrong!!

cheers!!!

 

[gracenote]

Thank you, Dolphin.

Is the full paper posted anywhere?

 

[Dolphin]

Thank you, Dolphin.

Is the full paper posted anywhere?

Not that I'm aware of.

 

[eric_s]

They study a group of people of which many probably don't have CFS (the "CFS" that actually means something).

Then they find these unwell people are more stressed than others.

Then they jump to the conclusion that stress leads to CFS.

And if that was not enough yet... they even get paid for that... plus some people will actually buy it and cause us even more trouble... then we will be stressed...

The only thing we can do is to stay cool and do whatever we can so there will be more real, good quality research and refuse everything that's based on this type of crap research. And do that in as united a way as possible.

 

[sianrecovery]

It sounds like a flawed study, and I intensely dislike the attempt to control ME by the psych establishment, but it also seems plausible to me that the experience of trauma, with its long term consequences for the endocrine system (another poorly understood phenomenon) may run alongside the later development of ME for some - and personally and and ancedotally among my ME friends I would say that there is an association. Not that that means a causal relationship obviously

 

[Snow Leopard]

It sounds like a flawed study, and I intensely dislike the attempt to control ME by the psych establishment, but it also seems plausible to me that the experience of trauma, with its long term consequences for the endocrine system (another poorly understood phenomenon) may run alongside the later development of ME for some - and personally and and ancedotally among my ME friends I would say that there is an association. Not that that means a causal relationship obviously

It might not be a causal relationship, but if they want to prove that their is a link, then they are going to have to do the longitudinal (and biochemical) research, otherwise their result may merely be due to a variety of other biases (such as participation bias - those who are stressed are more likely to want to report their stress in such studies). In the mean time, we can't conclude either way.

 

[sianrecovery]

yes, absolutely

 

[eric_s]

It sounds like a flawed study, and I intensely dislike the attempt to control ME by the psych establishment, but it also seems plausible to me that the experience of trauma, with its long term consequences for the endocrine system (another poorly understood phenomenon) may run alongside the later development of ME for some - and personally and and ancedotally among my ME friends I would say that there is an association. Not that that means a causal relationship obviously

I think such an association has been reported for other diseases (don't remember if what i read was about cancer) as well. It might exist, but the problem is that some people draw the wrong conclusions about the nature of the disease and about what treatment approaches are appropriate. I usually don't even read that kind of studies, feels like wading through ... It's also quite amazing how this can coexist with the developments in Norway and with other studies, such as the ones that have shown that infections can lead to ME/CFS or that there is abnormal gene expression after exercise, that we do much worse on the second day of a repeated exercise challenge, etc. I guess many people just work in their field, and will do so until it's absolutely impossible to keep their position and then they will stop altogether (instead of exploring different leads).

 

[eric_s]

I mean, just as a small example, not that it's very scientific. Yesterday at night, i was feeling quite alright. Because i'm leaving here tomorrow, i went to play billard with some friends. I like to play billard and i also like to hang out with my friends. Today, after waking up, i feel ill and have a headache. This is what i and probably many others experiece again and again. If you feel these things yourself, you know where your problem lies and would not waste your time with the crazy ideas of some of these researchers. [If you were a researcher yourself and your goal was to try to find a cause and a solution. I'm not talking about people on this thread here, but about the authors of these studies, just realized that what i've said might sound that way.]

Edit: Also ME/CFS often has a sudden onset. And once you have it, it does not just go away again after leading an easy life for some time, at least not usually. This just does not sound like a reaction to stress, maybe apart from stress weakening you and making you more vulnerable to developping this and many other illnesses.

 

[sianrecovery]

plus if you took any patient group -heart disease for example - and tried to make a connection between childhood abuse and its incidence you could probably manage it, because the statistical size of those reporting child abuse is a relatively significant one in the population at large, and its associated with worse health outcomes per se. Completely with you on the billards Eric, even pleasurable activites we enjoy can mess us up - its not about lack of motivation or avoidance