Folks with Bipolar II are more likely to commit suicide than any other type of bipolar.

Folks with Bipolar I experience mania.

It depends on what things you look at if you are going to say one is milder than the other.

I do not like hearing Bipolar II is milder than Bipolar I. I hear the person diminishing and dismissing the challenges of Bipolar II by saying that one suffers more with Bipolar I. The fact is both are horrible.