Symptom perceptions, illness beliefs and coping in chronic fatigue syndrome, 2009, Moss-Morris

I think you're missing the point that patients don't know what is happening in their bodies. Stress and infections, for example, can cause very similar physical symptoms. In the case of an infection the symptoms are mostly produced by the body itself.

 

This article is essentially an opinion piece. It cannot in itself be used as evidence for any of the claims in the article, as that would be a circular argument.

 

What is your definition of stress?

 

In the example I gave, anything that activates the sympathetic nervous system or CRH (which are normally activated in sync). Although that is just one aspect of stress.

I would disagree with this to a certain extent. Chronic stress can cause a number of long-term changes in the brain, so you may not necessarily feel "stressed", and those changes can last a long time.

 

I think we need to be much more specific when talking about stress in this context. When you say, "this is just one aspect of stress" I think that is an admission that stress for you is a bucket of all sorts of different things. This makes claims about the impact of stress unverifiable as if we examine one component of stress, you could always fall back on some other concept or combination of concepts.

If we narrow stress to sympathetic nervous system activation then I think we have a hypothesis which can be tested. But this is not the same thing as the experience of being stressed and needs to be separated out. When you say chronic stress, are you referring to long-term sympathetic nervous system activation in the same way?

 

Well, this is indeed a problem with stress. It has multiple aspects, but you can still test those aspects. For example, you can measure stress hormones, whether someone is feeling "stressed", whether they think their life is stressful, whether they feel overworked. Animal experiments can test forced swimming (physical stress), visible burrow (psychological stress), and can see how those affect brain structures and stress hormones over time. We can't do those tests in humans, and it's not possible to say definitively whether someone's symptoms are caused by stress. However, what we can say for certain is that stress can cause a range of physical symptoms and physiological changes in the body.

 

That is why stress is not a useful concept in this discussion. Stress can mean all of those things, all of which refer to different concepts and processes in the body. We need to consider each aspect of stress by itself, as if we want to find causes we need to look at specific pathways and interactions.

The issue for stress proponents is when we test these individual components we find no clues to ME/CFS. There isn't good evidence that stress hormones play a role. There are many people that feel stressed that don't develop ME/CFS and many people who aren't particularly stressed that do. Same with how people would describe their experience of stress. And as a result the concept gets made far more vague and far more untestable.

I think it is ironic that you say it is not possible to say whether someone's symptoms are definitively caused by stress and follow it up with a claim that we can know for certain that stress does play some role in the physical symptoms. You can't have your cake and eat it too.

 

If stress was the cause of MECFS would a course of benzodiazepines be a quick & effective cure?

 

We know for certain that stress can cause physical symptoms. We can't say for certain if one person's symptoms are caused by stress.

I think it is a concept that should be further studied in ME/CFS, as we do have multiple studies showing the stress is a precipitating factor, and that stress hormones are affected. Hypoactive HPA axis is one of the few findings that has been -- I guess you could say -- somewhat well replicated. Yes, nothing definitive, but certainly a worthwhile avenue for further research, and something that patients can address.

Klonopin and Ativan do seem to be effective in severe patients, according to anecdotal reports, although I don't think there are any RCTs. It's certainly an important avenue to research.

 

Lets say you had 100 people, and you went one by one and to check if each person's symptoms were caused by stress. You start at person 1 and get through all 100. But for every individual you aren't sure if their physical symptoms are caused by stress or something else. If there isn't a single person for whom you could say their symptoms are caused by stress, you can't then be certain that stress causes symptoms. It could be the case that for all 100 people you are in fact wrong and none of them have stress as a cause.

However, I do agree that under certain definitions, stress can cause physical symptoms. But I think we know that because we can test if any one person's symptoms are caused by stress. We can measure certain chemicals in the blood, check heart rate and blood pressure, the presence of sweating, and conclude that these symptoms probably result from their current stressful situation. If we can't test the connection between any one person's symptoms and stress we may as well say the symptoms result from an invisible symptom producing unicorn.

 

The problem is knowing what to measure, and being able to measure it. Also, the things you mention are all related to acute stress, not chronic stress, so aren't relevant to ME/CFS. There is no way to measure chronic stress in humans, although we do have more options in animal studies (e.g. direct measurements of vagal activity).

 

Even if stress is a factor in precipitating one person’s illness, it doesn’t follow that stress reduction will necessarily have any substantial effect on the illness. It’s entirely possible for something to “break” beyond what can be fixed by any stress reduction technique.

If you’re relying on anecdotal evidence, then take mine. I actually did have a period of stress prior to my illness, and it could have been a factor in developing it. But since then I’ve spent years on stress reduction. I’m pretty fantastic at it, actually, if you believe my therapist. Didn’t do a single thing for my ME/CFS. I’m not alone in that.

Again, I see a pattern of going between “stress reduction may be somewhat helpful in some people” vs. “ME/CFS is caused and maintained by ongoing stress and will be alleviated by stress reduction.” It’s either one position or the other, and the latter certainly isn’t supported by any strong evidence.

This forum isn’t hostile to the idea of stress reduction, that’s a perfectly great thing that everyone can probably benefit from. It’s pushing back on the idea that stress explains all (or even most) of our illness. There’s simply no strong evidence of that, and believe me, I’ve been looking. If you and I are on the same page about that, then there’s nothing further to discuss.

Side note: as long as you’re only in the realm of what’s possible, it’s entirely possible to have a mechanism that affects stress hormone production that is not dependent on ongoing stress stimuli. Addison’s disease, cushing’s disease, congenital adrenal hyperplasia, even in the unproven realm you could bring in any explanation that results in a lack of mitochondrial NADPH, which limits two steps in the cortisol biosynthesis pathway.

Stress hormone production is a multi-step process that can be interfered with at several points, many of which cannot be effectively altered by stress reduction techniques. Findings that show differences in any part of the “stress response” system in ME/CFS don’t necessarily implicate chronic stressful stimuli or a lack of effective stress reduction in the illness pathology.

 

Dundrum, you really have to start being more specific.

‘Stress can cause physical symptoms’ doesn’t tell us anything meaningful.

Are you aware of Wyller’s clonidine study on adolescents with chronic fatigue (I believe it might have been Oxford)?

They chemically surpressed the stress response and the sympathetic nervous system, and the patients in the intervention group actually got slightly worse.

I can’t find the paper, but here is a short report in Norwegian:
Auto translated:

https://forskningsprosjekter.ihelse.net/prosjekt/2012048

 

Stress is also a precipitating factor for many illnesses, it doesn't prove anything about the cause of the illness.

 

I could not remember whether I had seen this before. It turns out the journal is so obscure that University College London does not have an e-subscription. So I cannot read it.