I've not had therapy specifically for depression (although I have suffered from depression) but I've had plenty of therapy for OCD and other issues; I saw someone over several years.
Feeling that you need to go back for some 'top up' sessions might feel like a bit of a failure or a slip up to some people but I'd see it as pretty postitive myself, in that you're aware of how things are for you and have the courage to take steps when you feel you need to (I tend to adjust my medication and take steps when I'm aware that things are worstening for me).
There's something about 'mental health' issues that seems to leave some of us thinking that we ought to be able to stay on top of things all of the time, or sort it out for ourselves, I doubt that we'd be so doubtful about seeking help for a reccurance of a physical problem. Whatever you decide to do, it's your call of course but as someone who's have a longterm struggle with mental health problems my feeling would be to take what steps you need to keep yourself well and if that's therapy then why not?
I hope that it works out for you, good luck.