IMHO I would suggest you do NOT disclose your condition. Don't feel like you're doing something wrong by not disclosing it; you're not required to tell them. In my opinion, with such keen competition, many ad comms will not want to risk admitting someone that in the past needed to take time off school for a condition that though under control, still exists. Personally, I would think you would make that much more of a compassionate doctor, but that's just me.
As far as explaining why you took that time off school, only a handful of schools ask to explain any gaps so don't worry about that. From the secondaries that do ask, I remember Albert Einstein, Mount Sinai, George Washington, USC, and Stanford asked to explain any gaps. The 20 other secondaries I had didn't inquire about any gaps.
Good Luck