I got zap a lot of times when I was using (Haven't in a few years).
I got them a lot, but I also abused a lot, I got mainly from MDMA and got it a lot...I was new to drugs and totally freaked out when it happened quite a lot, actually ended up in hospital...
I got it really bad though.
My abuse was beyond abuse though, 3 sometimes 4 days of steady MDMA, normally mixed with some speed and coke.
It does go away though..it isn't anything I would worry about if you don't abuse, but I do think I had more long term effects, the zaps were 1 warning to tell me to calm down.