InfiniteSadness: I have the same problem. I used to be a lot quicker and sharper mentally, and now it feels like it takes everything I've got to follow a single train of thought for longer than a few seconds. I know that I'm smart; I just can't retain anything or follow anything, and my focus is shot. I know that having any kind of mental health issue has the ability to impair other cognitive functions. I have friends who have the same issue as well, so I know that it's not just me.