I was on Neurontin for I guess 3-4 years for RSD, doses as high as 5400mg/day. The doctors denied it caused memory problems; I have very little clear recollection of that time period, had occassionally nasty aphasia while on it, and my memory hasn't been quite up to par since. They denied it caused weight gain; I gained over 100 lbs. on it, which didn't start coming off until I switched to Gabitril. And though I had no known history of seizures before taking it, I had at least one (possibly two) full-blown tonic-clonic seizure after I had been on it for a couple years.

God, I hate that drug.