When people with ME/CFS report symptoms of post-exertional malaise, those symptoms are independent of emotional distress, but when the general population report what they think are post-exertional malaise symptoms, their symptoms of post-exertional malaise are significantly related to emotional distress. It is possible that because healthy individuals experience a relationship between emotional distress and post-exertional malaise, they might believe that these two domains are connected for themselves and by inference with patients with ME/CFS, when in fact it is not the case. This ultimately might blur the ability of healthy controls to understand the experience of post-extertional malaise for people with ME/CFS.
Of interest, a similar pattern occurred with the MFTQ factor Energy and PFRS Emotional distress, with a significant difference in the correlations between the ME/CFS group and the controls. Again, it is possible that the general population experiences a relationship between emotional distress and energy problems, they might believe that patients with ME/CFS not only have this same connection, but it might also be perceived by some as causal. In fact, the lack of a relationship between energy problems and emotional distress suggests that these two domains are not related among patients with ME/CFS. This observation is further supported by the finding that the Total MFTQ score among the control group is more highly related to emotional distress than among patients with ME/CFS.
http://dsq-sds.org/article/view/938/1113