I think it probably depends on what type of mental illness you have and it's severity (how well under control). normally I doubt it would be an issue but if you are not in control then your ability to be of help to others is really diminished. there might be some programs that would require you to disclose but I would imagine that most do not (altho with as I understand it therapy being a requirement for a degree...if instability is found then disclosure might indeed be an issue).

I think the problem might arise after the fact when you (the therapist) is already working. who is overseeing the program? what if your illness enters a crisis level and you don't recognize it? it can happen. not all of us are quick to recognize the slippery slope. and what if medication compliance is not 100%? those are important issues to consider ...and it's not just for psychological health but all health concerns .

it is important to maintain strong mental health & support through out the career