1) I wonder what that drug was that increased blood flow to the brain and returned cognition to previous levels?
2) Yes, slow processing speed. Can't follow some movies with the rapid changes in images at the same time as speech that may be too fast. Hard work to listen and process, as well as to speak. Uphill climbing. I have learned skills to improve my ability or performance--short cuts, what to pay attention to, how to relax everything not needed at that second, turning attention and its work on and off as needed. But this kind of efficiency and coping strategy has its limits. Failure happens more often and more quickly.
3) As for using more parts of the brain to do a simple task--yes, that corresponds with the amount of effort I feel I am expending. However, I want to say that I do not believe I was like this prior to ME/CFS, but only afterwards. There aren't studies of people before they get ME/CFS vs after, just comparisons with controls and what people report as their previous level of functioning, I gather.
4) Decision making is so poor in my case--I would go round and round and never be able to put it all together and assess things in relation to their context, my needs and goals, etc.--that I have taken to dowsing to make most of these decisions. If I still had a dog and could ask the dog, I might do it that way! It is simply too difficult if not impossible to make all the decisions otherwise.
5) And as far as those cognitive tests still coming up with the conclusion of depression, I think this is how the tests are structured and written. In other words, even though you may say you are not depressed, if you report low energy and memory or cognitive problems, the built in interpretation of that on the test is that you are depressed. This is called tautological ? There is some term for the logical loop or dishonesty involved, but I am not sufficiently knowledgable in the realm of logic to say. In layman's terms, the tests are rigged to show whatever the writers of the test already believe.