Disclosure of history of depression
It would seem weird for you to disclose your issues this late in the application process (a week after they said that they'll "announce shortly"). Even if there was some benefit to being honest about your past, it's probably too late to do it now. It would have been a good idea to mention your past problems, how you dealt with them, and how you are feeling now if it would give a better impression of your current state, at some point early on in the process, e.g, during the interview, preferably brought up by yourself, but if you contacted them about it now, it would seem more like a desperate attempt to salvage an application process you think is failing (even if it actually isn't).

Even if it could make a difference between being accepted and not being accepted, you have to then wonder why the commitee haven't brought it up themselves then? If this is the issue that'll be the decider here, then I find it highly unlikely (and highly unreasonable) that the commitee haven't given you least a chance to talk about it from your perspective. So, if they know about it and haven't brought it up, it's probably not what's going to decide whether you are accepted or not, so bringing it up now is likely to have no effect.

But, if there's a next time, and you're sure it will be mentioned in your recommendations letters, then bring it up yourself. But remember, nobody is expecting you to disclose the detailed circumstances of what and why. That's your private life, it's nobody's business. But you should at least explain how you overcame it and how you are feeling now. and make clear that it's entirely in the past now (if that's true, obviously, but I can understand how you may not be fully aware of whether it truly is in the past yourself. Just make sure to act in good faith).