This is a hypothesis not a study so don't expect to see clinical trial type data, so in those terms it is not meant to be 'very scientific'.
PNI research is in it infancy, it does attrack the odd bonkers looking hypothesis but IMO it is important that theories can be put out there to debate and discuss, however, uncomfortable they may seem or what buttons they may trigger in us.
As Dom said it is a)good that researchers are exploring other avenues and b)there is a worry that this could be simplified or misinterpreted to mean it is saying postive thinking is all you need to do or indeed that stress causes MS. Which is not
what this hypothesis appears to be saying to me; only that these factors alter the biochemistry of the brain and this in turn may exacerbate MS.
I don' think anyone at this stage can say stress doesn't play a part and by this I mean long term chronic stress or indeed enivronmental or underlying clinical depression or range of other factors that underline the interplay between the immune system, the endocrine system and the psychological dynamic.
In the last two decades medicine is breaking from the concept of 'mind' and 'body' are separate and recognising the interelationship. Nor should it make any one uncomfortable, though it is understandable why it does and why people, with various conditons, are resistant to contemplating this. In MS ,maybe, because it is so often, for many people with MS, that they endured 'well intentioned' family and friends or even not so well intentioned telling them it is all in the mind. This is crap psycho-babble and nothing to do with PNI or what PNI is about.
Chronic stress plays a role in many conditions so why not MS? What makes MS so exclusive that stress or any negative thought pattern does not play a role? Maybe it plays a role for some people and not for others? Maybe it is more applicable to some types of MS and not to others. Who knows and that is what a hypotheses is about-exploring.
Unfortunately the self help business takes things to extremes and does over- simplify what is a very complex and biochemical process and interelationship. It still can help a lot of individuals so I am not knocking it but PNI is not self help in the literal sense promoted by self-help but a recognise bona-fide branch of medicine and science
Here are few studies of PNI and the interelationship to disease that may illustrate
Depression and immunity: inflammation and depressive symptoms in multiple sclerosis.
Cousins Center for Psychoneuroimmunology, Semel Institute for Neuroscience, 300 Medical Plaza, Suite 3109, Los Angeles, CA
Endocrinology: the active partner in PNI research.
Department of Internal Medicine,The Ohio State University Medical Center, Columbus,
Psychoimmunology: a questionable model?
Service de medecine interne et immunologie clinique, Hopital Jean-Minjoz, Besancon, France.
Conceptual development of the immune system as a sixth sense.
Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, AL, USA.
Psychoneuroimmune implications of type 2 diabetes.
Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801, USA
In my work I see first- hand the effects of emotions on thought and the effect of thought on the physical body and mind. I see it in myself too.