In my experience as a therapist who helps people with bipolar disorder stabilize themselves, one of the challenges has to do with getting them to be more in tune with their circadian rhythms. This is the body’s internal chemical clock whose impulses regulate the our sleep and waking cycles, our appetites and our moods. Most of us stay tuned to our clock, especially if we have a regular schedule, and have good habits around diet, exercise and imbibe with moderation. When we get out of sync, it’s usually not by much and we seem to adjust accordingly. People who have bipolar seem to be more out of touch with their circadian rhythm and when they do, it’s much harder for them to adjust. In this light, mania can be seen as a complete breakdown of the regulation of our internal clock, or at least ignoring the signals. This is why it’s extremely important for people with bipolar disorder to keep to a schedule and to listen more closely to signals our clocks send us.
There is a very good, concise article about this at Psych Central by John Grohol.