I have a relative with severe rapid cycling bipolar, who is also, very intelligent.
You could always seek out a professional who specializes in gifted to help you sort it out, find out one way or another.
I am not a professional, but feel free to PM me if you want to talk at all about it. I have lots of experience with this relative.

Here is a link I like about OE's

http://www.davidsongifted.org/db/Articles_id_10102.aspx

Incog