I suspect Bi polar....its the odd stuff and the complete change of personality rather than just down, and by saying "just" I hope not to offend as being down all the time is equally horrid.
I can relate to down times, one down time was when I first divorced, had a new life, left my daughters with their dad mainly due to finances as I was off to university, that was my big down time, my Brain was like fluff, I could not read, had no interest in anything and not able to think or want to think.....thankfully that was sorted, I did at that time write a list of things I could change and things I couldn't and worked on them starting with the easiest first, that was University and lack of money, I was extremal lucky to get 2 jobs that I hoped would work together, one was high powered and the other was a care job, the care job got me through my dark mood and the high powered one gave me status, I even had to mix with royalty but the jobs were knocked on the head after a year as I took up Fostering, I loved that, well for 6 years I loved it, in that time I also trained in drug counselling and carried on my youth work, those bad times became very good, plenty of me time to be with my daughters, plenty of money (who says money does not buy happiness?) and a wonderful new relationship. Anyway, all it boils down to is circumstances, things could have gone Soo wrong but for me they went very well.
The worry about things such as Bi Polar, they are hard to diagnose unless the person does something very public, that Stephen Fry programme was wonderful and it certainly got a few acknowledgements in this house.
Sometimes, to get a diagnosis is a very scary thing, but its more scary for those who care when there is no diagnosis, predicting mood swings becomes something you become preoccupied with.
Anyway, I am becomming far too open for a small holding forum

I have tried other forums but never felt comfortable, on here I do, certainly glad I came back