Well, Little Bluestem, people with ME/CFS are on a spectrum and there are probably subgroups. Also it depends how long you've had it, in combination with its severity. But there is evidence through brain scans that our brains show changes. I personally consider it damage, but can also go with a more neutral idea of dysfunction or changes. Anyway, I've long thought that there must be a problem in the area of the dopamine-producing area in the back of the brain, the reticular activating system. Dopamine is the neurotransmitter which enables brain speed. I know my brain slowed down once I got ME/CFS, that it is like someone's who is half asleep all the time or clonked with the flu. It is constantly "dropping the ball".
So I tend to think medications or supplements which might help with dopamine production and functioning would be helpful. People with Post Polio Syndrome have damage in the part of the brain as do people with Parkinson's, though the damage with Parkinson's focusses more narrowly on the ability to move. I don't know about amantadine varieties, history or anything, PNR2008, but what I read in this article. I would really like more medical research and treatment aimed at the slow forgetful brain.