I have been experiencing this electric shock sensation in the back of my upper left arm and my armpit for a couple of years now on and off. It seems to be worse when my clothing rubs on a certain part of my arm. I get the sensation of a rubber band snapping under my skin and it can become quite painful at times. I started taking Celexa 20 mg around the same time. 2 months ago my dosage was increased to 40 mg and I am now experiencing the same pain although not as bad this time. I have searched endlessly on the internet for possible reasons for this....one has to do with perimenopause which is possible as I am 43 and have experienced a few other symptoms, the other being discontinuation syndrome...the last time this happened I hadn't been taking my meds regularly as I kept forgetting and as soon as I realized this I took them regularly before bedtime and it went away. Now that I'm on 40mg, I haven't missed a dose but I have the pain again. Just wondering if this is a possible side effect of the medication. I've also been told that after so many years of having back surgery nerve damage can happen and I had back surgery 16 years ago. I'm truly at a loss here and don't know where else to look.