I take 400mg of Lamictal and have been for over two years now, but lower dosages for at least 5 years or so. My memory has been awful. I just noticed how bad it has become over the past several months. It's awful. I recently added Ritalin to the mix to help with depression and give me some energy, so I don't know if it could be from that? I also take Topamax which is known to make you "stupid".