Lots of good points in your post, biophile. I'm afraid it's one area where I find I'm not so good at remembering the findings. I tend to think lots of people who are supposedly in the "pre-morbid" stage aren't at all but either have ME or CFS (or might have had in the past and are in a period of remission/relative remission which might still alter their responses e.g. about ever having depression). Also, the studies tend to highlight the positive findings and often don't explicitly highlight (or highlight much) the areas where they found a lack of association - so one factor could be found to be associated in one study, but not in two others, but people tend to remember the study where it was associated. Anyway, that's my excuse for not remembering it but maybe other people can remember what you are asking about.