Reminds me of this article: http://www.lambdassociates.org/blog/bipolar.htm
I don't like the dark side, I hate to see all the beauty I create when I'm 'high' dribble through the impotent hands of the dark periods. But I've come to accept that this is how I am and always will be.
My only way out of the hole is to try and steer clear of addictions and learn new stuff.
Since I can't do anything of practical use during this period - nothing is exciting, the world is going to hell, I'm a failure and cannot do it, etc, I use the time to learn new stuff, read books on every possible subject and just try not to be too big of a drag on those around me.
I've been here multiple times and I know that each 'down' period is followed by a rush of energy and creativity and I have to be prepared with knowledge and health so that I can apply it during my 'mental spring'. This is how I've created great stuff before and I will in the future. At least this is my hope.
At the moment, learning lisp is a kind of psychotherapy that I apply to myself and it seems to be working, even though I have no idea what to do with that knowledge, it will soon all make sense.
Brilliant is impossible to be, what we can hope for is moments of 'brilliance', where one can come up with original solutions to problems. Ideas, revelations..
I do have those from time to time and it feels great.
But as a human being, it does matter what and how you feel in between those moments of brilliance.
And during a 'low' phase (which can last months, day after day), all your moments of brilliance are replaced with mental blocks, melancholy, cynicism and pessimism about everything and everyone. It's a very bad place to be, it's painful, the feeling of being a fraud, the way you disappoint yourself and others by not following through, the way you see your dreams and hopes drown in a sea of confusion and frustration. When everything you've earned/gained is slowly erased and you have to start again from step 1.
Yeah, I think that's a problem. You either kill yourself, drink/drug yourself to death or find a way to cope with it. My solution is to just obsess on books/studying new stuff when the mental winter comes and try to stay away from the easy escapes.