I have BP II but have always related to cyclothymia because my depressions are usually pretty short (anywhere from 1 month to 2 days). Sometimes I think I used to have cyc and "graduated" to BP II. Anyways, as others have mentioned, treatment is generally the same, though you may be able to withstand antidepressants better than someone with BP 1.

As far as co-morbid disorders, anxiety anxiety anxiety. For me at least, and I would expect the same for most people with any kind of BP.