Yeah, my friend I had the hyper-intense hangout with 10 days or so ago is not diagnosed bipolar (I have a hunch that's wrong but whatever) and I guess crashed pretty hard afterward. They didn't go into a lot of detail, at least not yet. I was quite unstable for a couple days after but my mood was generally good. That friend is also super high empathy, to the point where it causes them problems (can't deal with killing a bug for example due to horror over what it might feel).

I went to my psychologist today and brought it up and he said ON AVERAGE bipolar people tend to be less empathetic than the general population when they're too far up or too far down, but normal when they're stable or in the middle moodwise. He said I'm an exception due to having very high empathy, and that selection bias is probably why most of my friends, including the bipolar ones, have high empathy. Simply put, I'm drawn to those people so there are more of them in my friends group, which includes bipolar people.

He also brought up the idea of mutual resonance, especially between two bipolar people - both spinning up into a feedback loop which, as happened with my new friend 10 days ago, can sometimes turn into a runaway feedback loop. At the same time, one of my bffs is bipolar and we absolutely have mutual resonance but not of the type that will turn into a runaway feedback loop. It's self-limiting for whatever reason.

I'm pushing 40 and there is always more to learn. I guess I just have to be mindful of this stuff, especially when dealing with friends who are also unstable. If I can learn to remember to recognize when it's happening, it will help... I'm pretty good at dealing with other people's and my own needs in a social context IF I am aware that it's an issue.