A diagnosis of Cyclothymic Disorder requires the presence of numerous hypomanic episodes, intermingled with depressive episodes that do not meet full criteria for major depressive episodes. The main idea here is that there is a low-grade cycling of mood which appears to the observer as a personality trait, but interferes with functioning.
http://www.mentalhealth.com/dis/p20-md03.html

bipolar 2:

http://neurotalk.psychcentral.com/sh...517#post396517

this is a rather long description of bipolar 2 the more depressive side of bipolar. it too has some hypomania as well.
just thought I would post this for you.