I know that when I am in a low or high mood my memory gets slurped down a tube. I have the
memory of an elephant, or at least I had. I had my
Lamictal upped and it has in general (when I'm not in pain) raised my mood and it's made me have clearer thinking.
You are on a pretty low dose of Lamictal, it could be that you aren't in a "therapeudic range" for that or some of your meds, but that's only a guess, you should speak to your pdoc about your memory issues.