Your health condition is good now, but it may not be at some future point in your life. For a vocations director to sign off on you, he’ll have to have a relative certainty that you will generally be able to fulfill the duties enjoined upon you throughout your career. Chronic illnesses, whether physical or mental, therefore often present a barrier.
I’d encourage you, though, to have words with your diocese’s vocations director, or that of the society or institute in which you find yourself interested, and to be very straightforward about your mental health history. If you can’t, then it’s better to know up front than to get too invested.