Yes, omega 3 is good for the brain.
But, they won't help bipolar spectrum disorder.
There's a link up in the stickies from the NY Times about bipolar disorder. There's also good information here:
www.psycheducucation.org And there's a few threads here on the forum dealing with bipolar issues. I urge you to check these resources out.
But, beyond medication and counseling to learn to live with bipolar disorder, there are behaviors that can help you manage the symptoms too. Some have been mentioned already. Healthy eating and exercize regularly. Keeping a regular schedule. Sleeping 7-8 hours a night. Practicing relaxation techniques when necessary. Enhancing your spiritual practices. Improving your self esteem. Maintaining a healthy balance between work and home.
I wish you luck and hope to get to know you better.
Shalom!