I put can't estimate. 57. First major depressive episode was at 20, preceded by having a LOT of fun and sociability. So...37+ years. But knew pretty much nothing about BP, and never thought to consider it because it was the depression I was aware of. Somehow, despite copious evidence, I didn't actually get dx'd till like 44 (why can I never remember exactly?!) Major AHA time when BP was revealed to me. And then the looking back started. There were many, many times when it seemed hypomania was at play. I'd scarcely know where to begin.

If/when I crossed over into mania, I don't know, seeing how the line is not always obvious, and I don't recall anyone telling me specifically. (Hence my confusion over the II and I dx's-- I think it was hallucinations that caused them to change it, but again, no one told me). But hypomania? Lots. (Not so much anymore, but when I was younger, it was left and right.)