I personally wouldn't fast on any medication, but I have never accepted any anti-depressant medication prescribed for me so my case doesn't apply to you.
I have heard that anti-depressants are safe to continue while fasting, so maybe your bipolar medication will be fine too. However none of us here are doctors that I know of so we can't advise you specifically. You will find on this website a list of fasting retreats around the world, any of which would be glad to offer you advice no doubt if you contacted them. Also there is an Advice page which there are some experienced Fasting Supervisors offering consults and some also offer advice through the forums there:
Even if it is safe to use your medications while fasting, their effectiveness may change while you are fasting and the dosage may need to be monitored. There is also a Depression forum here on Curezone where I know they offer advice on dealing with your condition without medication through diet and other ways so that might be worth looking into also.