Can I take vitamin B complex while on antidepressants?

If there’s any way you can avoid those meds—assuming you aren't actually spiraling—just stay away from them.
You'll just end up hooked, and they’ll fry your brain in the long run. I’ve seen too many cases with older folks, people over 60, turning completely senile, and it’s probably because of pills like these.
Stick to natural stuff. Honestly, don't even bother with vitamins; just eat plenty of fruit and get what you need from there.

And whatever you do, do not mix birth control with antidepressants!