I think it is a good plan, but, based on my LOCAL (Silicon Valley) experience, do not mention bipolar right off the bat. You can mention depression and anxiety.

This is from my local experience - locally, here, depression and anxiety are mentioned completely casually during catch-up coffee dates with someone you have not seen in a few years, etc. Depression and anxiety are mentioned without any prompting of any sort. Last time it happened to me - I had a catch-up lunch date with a woman whom I last saw in 2008. She did not eat some sort of a typical food based on wheat. She told me all about how she avoids gluten in order to combat symptoms of depression, and how well the gluten-free diet is helping her, so that she does not need medications.

Did she have to say it?

No.

She could have just said that she was gluten intolerant, as many people are.

She chose to disclose the symptoms of depression.

And it happens all the time.

Bipolar and schizophrenia, though, remain serious illnesses and not something you just mention casually in-between the main course and dessert.

And that, too:

if you start talking about it, chances are that either he or his brother... you get the point. It is a fairly safe route. It is depression, just that, depression - you are not hearing voices.