@Hip Not everything that goes wrong with us is going to be related to a virus or an infection.
I already indicated that I accept that stress and psychosocial factors are involved, but my view is that you just don't stop looking for other possible causal factors just because you have found one factor. Diseases are often multifactorial.
Even with ME/CFS, if enteroviral or EBV infection turn out to be the primary cause, it is still likely that ME/CFS etiology is multifactorial, and a virus alone may not trigger it. It may require the presence of several other factors in tandem with a virus to trigger ME/CFS.
I'm not sure why you find this so difficult to understand. I'm guessing that you have never been in that position yourself otherwise you would get it.
Actually, I have been in a similar position myself, which is what has informed my ideas about burnout and nervous breakdowns.
Long before I had ME/CFS, I was hit by what seemed to be a kind or nervous breakdown / generalized anxiety disorder. I was working as a digital media computer programmer, an interesting and quite low stress job that I really liked, and everything was going very well in my life (in terms of friends, relationships, etc). In fact it was one of the happiest and most interesting periods in my life.
Then out of the blue, for no apparent reason, I started to develop significant anxiety. I began to inexplicably become fearful of flying, and I developed a weird autism-like anxiety when meeting people socially. Being with friends or work colleagues became a horrible ordeal of anxiety; normal conversation and social interaction triggered this autism-like mental tension (except for some reason when I was with my long term girlfriend, or with close family). (This is not what is classed as social anxiety; that is quite a different thing.)
I struggled on, but eventually the autism-like anxiety made my work almost impossible, because all face to face social interactions became very difficult, and so I dropped out of doing work more and more (I was working freelance on short term contracts of a few months, and started to take on less and less work, because it was too much for me). My work also became difficult because my illness affected my cognitive performance. And I had increasing fatigue, making it hard to get up in the morning. And I had some mild depression.
My worldview also turned quite bleak and cynical. I am usually very optimistic, but suddenly I became pessimistic about the world and the people around me. I started to think that everyone's motivations were rather base and cynical.
Along with these mental symptoms, I also developed physical symptoms: chronic severe diarrhea (which lasted for many years), which I think was IBS-D. And very tense muscles throughout my body. It is possible that the mental symptoms could have been the result of severe IBS, because anxiety and depression can come along with IBS. However, my mental symptoms were strong enough to destroy my career, and eventually my relationship with my girlfriend (which had been going very well for many years until I became ill), so I tend to think of my experience as a kind of nervous breakdown.
My best guess is that I contracted some type of gut infection that triggered the IBS with severe chronic diarrhea (my mother also developed IBS out of the blue more or less at the same time as me, suggesting an infectious cause going around).
Because my life was so easy-going, stress-free and happy at the time, there is no way I can put down my sudden onset nervous breakdown-type symptoms to psychosocial factors. To my mind, there had to be a physical cause, such as an infection.
