A comparison of the cognitive deficits seen in myalgic
encephalomyelitis to Alzheimer's Disease.

Scholey, A et al. 

Proceedings of the British Psychological Society, 1999, January, 12.

Another symptom which is characteristic of ME is impaired cognitive
functioning (e.g. poor memory etc.). 
Early reports revealed major deficits, but these were forgotten when
the research found only subtle changes in CFS. The following study is
noteworthy because it focused exclusively on people with ME (London
criteria). Tests were done on 20 patients and it was found that their
performance was significantly inferior to that of healthy controls.

Moreover, when the results were compared to those from 782 patients with
Alzheimer's Disease (AD), the ME group fell between mild and moderate
Alzheimer's patients on most tasks. "The extent as well as the range of
the impairments ... confirms the severe nature of ME."

These findings deserve to be taken seriously because they were reported
by one of Britain's leading experts in the field. The results not only
support anecdotal reports from patients but they underline once again 
that generalisations about CFS may not apply to the various subgroups.