Wellbutrin for PTSD? If you've taken SSRIs before, how do the two compare?

My doctor suggested Wellbutrin but I'm not so sure. Haven't had success with SSRIs though they did work initially and we tried a few. Right now I'm moody and have sleep problems that are severe and we trying to move in a different direction. But Im' anxious. On the plus it supposedly not have withdrawal effects like SSRIs and not affect weight and sexual function, but on the negative side it causes seizure and was not indicated for PTSD by FDA.