My father is bipolar. Went to med school, failed a few exams, abused substances to pull himself through the stress and grind, and eventually became a successful neurosurgeon. Then about 15 years ago he quit for no apparent reason, and has been in a deep depression since then.

So it's possible. I'm not sure why you'd want to do it med free, however? I find that even a low dose of medication helps me (given that you have the correct med routine). This said, as much as I wanted to enter the healthcare profession, I ultimately decided that the potential burnout was not for me. Sleep deprivation has triggered psychotic breaks for me in the past, and that's something I'm not willing to risk. Also, such things can affect the credibility of a doctor.

So ultimately, I guess it's about knowing yourself, knowing the profession, and whether you think that it's a challenge you're willing to take. I like jesusplay's suggestion of talking to your medical team, as they'll be able to give you more precise feedback. Good luck.