Unless it impacts your ability to practice medicine, it should not affect licensing. As I understand it, in the states that ask, you have the option of disclosing IF it impacts your ability to practice. If you believe that it does not affect you in that way, then simply do not disclose it. This, like any medical issue, is an extremely private matter and protected medical information. If during residency your MDD affects you and you need to talk to your PD about it (say, to take a LOA or request accommodations) you could simply disclose (and have your treating psychiatrist confirm) that you have MDD that requires accommodations.
Edit: the above poster stated that some states require disclosure of all psych conditions. I was unaware of that, or of which states do. If your state does, you should be fine, and you could just disclose MDD. If your psychiatrist is unwilling to amend the diagnosis, you could certainly find another who is willing to do so. As I see it, simply stating that you have MDD is still accurate.
Obviously just an M2, so take the world of practicing lawyers/physicians above mine. My knowledge just comes from researching issues with disability in medicine and from prior legal/policy work.
No, you often can't get providers to amend the diagnosis, if it's accurate and based on the facts of your case. Even going for a 2nd opinion and doctor shopping.
Some states will require full disclosure of ALL psych diagnoses EVER, but that's a small minority. I imagine any state is used to seeing MDD on the list, and it's possible even that they might ask to see all your medical records as a condition of licensure (to be clear, you could say no to this request, but as you might guess...)
However, if it has never interfered with your ability to practice medicine, typically everything goes smoothly, aside from if they need to see your records, and even then, that usually only delays things if anything. If you had to take a LOA I'm not sure how you should best answer this, as I'm not sure that affects your practice of medicine besides having a leave, where you are not practicing medicine. I'm splitting hairs. You should still probably answer yes, and mention the LOA (that's actually an appropriate and less concerning way for you to handle severe mental illness in medicine). If it clearly affected your ability to practice, and especially if there is evidence of that via your medical records, school, or otherwise, then you must answer yes, unequivocally.
It gets a bit murkier if the question is worded, "or
could ever affect your ability to practice." I think you can use your judgement here. If your depression was precipitated by a particular time limited event and you have recovered, I think that's reasonable here to answer no. If you have a chronic mental illness, I think you need to use your judgement.
Also, NEVER lie to the medical board. That has the potential make your clinical career toast forever. You don't want to appear to be lying either, so an LOA 2/2 MH is likely a reason to answer "yes" to any question about it affecting ability to practice, to be clear.
Almost every state licensure form I've seen (and I've seen quite a few) even if you answer it has not affected your ability, might ask if you've ever been psychiatrically hospitalized (think about it, you could have been psychiatrically hospitalized before ever being a med student, in which case, you would say no it has never affected ability to practice, yet answer yes to the question of being hospitalized). This is a much bigger deal.
The advice I was given by a psychiatrist that specialized in treating physicians with mental health issues AND dealing with the medical board of my state, recommended that if such hospitalization was necessary, to receive it outside your home state and the state of practice, and private pay out of pocket. I think they said there was somewhere good in New Mexico or Arizona. I think the implication was to make it easier to hide the hospitalization. I don't want to discourage people from getting help or encourage lying or hiding anything to any regulatory board, but given what a big deal even voluntary psych hospitalization is as far as your career and licensing, and how such stigma leads people to not seek such care at all even when needed, I think I would be remiss if I didn't pass along the advice of this psychiatrist.
Lastly, some states ask the question about psych dx in a certain way that even if you can answer honestly without disclosing anything, they might ask what medications you are on and for what condition they are for (so even if you take propranolol for anxiety, depending on the form it may or may not be clear why propranolol). In that case, they're going to figure it out if you are still on meds, and may have questions.
The fact your depression was precipitated by a major life stressor that is not likely ongoing, and I'm assuming your depression is under control now, with or without ongoing treatment at this time, and that it is not
currently affecting your ability to practice, even if it has in the past, leads me to conclude you could likely feel free to disclose on any of these forms and have no problems ultimately obtaining licensure. As I said, typically the worst thing that might happen is that they may want to see your records or obtain a note from your treating provider that you are fit for duty. Some cases, you might have to see a provider of their choosing.
Honestly, I really don't think you need to overthink this, I think you can be 100% honest, totally disclose, and not have any issues.
I went into so much detail, because often people will either state psych dx disclosure on license forms is "no big deal" or they tell you that you will be screwed. The answer is actually in the middle and more complex than that, and varies by state. Also, many don't know about the implications of psychiatric hospitalization. I've read more than one state law and licensing form on the topic. Every time it comes up, I just try to dispel myths, provide information that may or may not be useful to anyone reading SDN. You never know when you or a colleague will be a situation to need to consider these issues. MH changes over time, and as I'm sure OP is aware, life can always bring us new medical diagnoses.
You can read my past posts and that of others on this board on this topic.