None actually but another thing about the syndrome is that the cause is not understood, even though there are proposals like biological mechanisms or psychological ones.
I had mono as a child, but if I understand correctly the cause of CFS is not completely understood.
Have you ever heard of Chronic Fatigue Syndrome? Yes, since the diagnosis depends on the person's symptoms. There has been very little research until recently and it was often misdiagnosed as Fibromyalgia. Many doctors think its linked to the Epstein Barre virus which causes Mono. Do you know anyone with Mono or Chronic Fatigue Syndrome?
Biological, genetic, infectious, and psychological mechanisms have been proposed, but the cause is not understood.