Joan - I don't have any idea exactly what Amantadine does but it seems, at least in the past, essential for my being able to move without suffering very incapacitating freezing. I get my drugs through the mail and, about two years ago, had neglected to send for a refill on time. My neurologist didn't think that skipping a few days would make any great difference, but it did. It necessitated using a wheelchair for the time I was without the medication and it took a couple of days for it to take effect again after getting the refill. I don't think this was mental, and I have never tried doing without Amantadine since this experience. Joan Holliday 64/21 [log in to unmask]