I'm just curious if anyone has been on Namenda and could tell me how long the initial brain fog lasted for you? I just started Namenda yesterday, 5 mg a day for 1 week then 10 mg a day in divided doses. I have memory issues and severe cognitive impairment. I was put on Namenda by a neurologist after a thorough examination. I expect the brain fog from starting Namenda up but am just trying to get a time frame for when I could expect the initial brain fog to wear off. Thanks everyone.