Hi,
Yeah, that was a big frustration for me--I require a LOT of mental agility in my job, and it frustrated me to no end when I would hit those "blank spots" or seem to be unable to even get my brain in gear.
Everyone is different. For me, it took several months before things cleared up significantly, and today, at almost two and a half years sober, the cognitive brain functions seem to have returned to ALMOST the pre-abuse levels. I believe there will always be a residual effect on me, but nothing I can't live with.