Bipolar II disorder refers to a mood disorder in which a person is mostly depressed (sad, despondent, guilt ridden) but has also had one or more episodes of mild mania (hypomania ); a condition with only mild manic phases, characterized mostly by agitation or anxiety.
Moreover, Bipolar II disorder refers to the same patterns of symptoms found in Bipolar I, but without the same degree of disability. Bipolar II disorder is less severe, does not lead to psychotic behavior, and typically does not require hospitalization.
Other /More definition:
Bipolar II disorder refers to the diagnosis used to describe a clinical course in which the individual experiences one or more major depressive episodes and at least one hypomanic episode.
Other /More definition:
bipolar II disorder refers to alternation of major depressive episodes with Hypomanic episodes, but not full manic episodes.