This is quite interesting for the writer-types around here: http://www.independent.co.uk/life-style/health-and-wellbeing/features/creative-minds-the-links-between-mental-illness-and-creativity-1678929.html
For what it's worth, I reckon the majority of us have some sort of depression-related illness minimum, though my personal view is that we're all on scales of different 'affectations' -- ie we're all somewhere along the scale of manic-depression, obsessive-compulsiveness, synaesthesia, rather that being manic-depressive or not. I don't think it's so black and white.
For what it's worth, I'm pretty sure I'm mildly manic-depressive/bipolar. Often having those manic days and, more frequently, depressed days for no particularly reason.
I know there are at least a couple of Asperger's sufferers that read around here too.
Wondered what other people's thoughts were.
It will allow me to wallow in self-pity and over-analyse, if nothing else...
Dan