The following comes from psycheducation.org, a website that deals primarily with bipolar 2 and the bipolar spectrum:

It's true that hypomania is a milder version of mania -- just how mild, you'll see in a moment. Mind you, Bipolar II is not a milder version of Bipolar I, though it is very often described that way, to my utter dismay. The suicide rate in Bipolar II is the same or higher than the rate for Bipolar I, for example.Dunner So the BP II version is definitely not a "mild" illness. The depression phases are as bad as in BP I, and often more common (that is, they occur more frequently and represent a more dominant part of the person's life).