It's not true that manic people don't sleep at all, but we do tend to run on far less sleep than the average person. I was in a psych hospital with a disgnosis of 296.44 Bipolar I Disorder, Most Recent Episode Manic, Severe With Psychotic Features and usually managed to get 2 to 4 hours of broken sleep.

Plenty of people go months or years without an episode. When people talk about rapid mood swings in Bipolar, they mean that the patient has 4 or more mood episodes in a calendar year. There are very few people who have ultraradian mood swings, but it's happened before. When people have rapid mood swings in a very short period of time, pdocs generally suspect borderline rather than bipolar.