pale.emperor,
In 1990, it was calculated that 5% of the publishers in our circuit were suffering from M.E. (or Chronic Fatigue Syndrome - CFS - as it is now most commonly known as). I recall its victims including Special Pioneers and the like. It even seemed that the more "active" you were in "Jehovahs Organisation", the more likely you were to be afflicted by M.E. / CFS. Youth offered no protection, either. In our congregation, even some children were suffering from M.E. / CFS.
However, in the 23 years that have gone by since I broke with that lot, I have known only one person who was diagnosed as having that complaint. It would seem that it does indeed afflict JWs more than the population in general.