There is some considerable debate about whether or not chronic fatigue syndrome (CFS) is a psychosomatic disease.
Certainly - in my time at least - it was prevalent amongst the JWs. For example, back in 1990, it was estimated that 5% of the publishers in our circuit were affected by this condition. It was noteworthy, too, that it seemed to affect mainly the most "zealous" of the JWs - the "pioneers", missionaries and similar.
Significantly, since breaking with that lot 28 years ago, I have only ever known of one person who suffers from this illness.
CFS used to be called the "Yuppie Disease". It might as well also be named the "Dubbie Disease"!