Bipolarity

I've scoured the internet, and I've found a lot of sensational info, some of which I do not believe at all(like people speaking with different accents when depressed). I'm sure a load of you's guys have a more than general knowledge of bipolarity, so I'd be very appreciative if you could direct me to a site with accurate information.

This isn't for a school assignment, but rather a checking up on a questionable diagnosis.