Clinical experience shows that medications like Ritalin and Dexedrine (amphetamines) can be very helpful in a subset of people with chronic fatigue syndrome — particularly those with low blood pressure issues (called orthostatic intolerance) such as POTS and NMH.
Although these medications are (imho) grossly overused in hyperactive kids, I think they're underused in CFS and fibromyalgia.
Now, a new study shows that an amphetamine medication called Vyvanse was helpful in CFS, at 30, 50 or 70 milligrams (mg) daily.
I prefer Ritalin or Dexedrine to this medication, and at a much lower dose of less than 20 mg a day, as we start to see addiction issues with larger doses. Interestingly though, people with CFS under 18 years old often need higher doses, closer to the doses used with ADD, while those over 30 usually need just 5 to 12.5 mg a day.