I was wondering about this just yesterday!
I've been on zoloft (sertraline) for 2 weeks now and I have not cried a single time, when before I was crying at the slightest thing every day. However, I feel a constant pressure behind my eyes and want to cry, I just can't, it's driving me insane. But I don't feel numb at all, quite the opposite, the sertraline is reallly not working for me and has made me feel really really bad, I just can't cry for some reason.