Yes. I have stopped and then restarted Paxil, Celexa, and Effexor (SNRI).

Paxil worked both times, but made me REALLY sleepy on attempt #2. I then switched to something else.

Celexa worked both times, but I was more depressed on attempt #2, so I believe I took a higher dose.

I am currently on Effexor for what I think is my third lifetime attempt. It has always worked for me, it's just that I've stopped intermittently for dumb reasons. I ain't no doctor, but I am a medical student, and it seems to me that if you take enough of something with that strong an effect on norephinephrine (a close relative of adrenaline), it's bound to work whether you've been on it before or not. The pure SSRIs are maybe a little more mysterious.