What are the three levels of bipolar?

Bipolar disorder is typically classified into three main levels: Bipolar I, Bipolar II, and Cyclothymic Disorder. Bipolar I is characterized by at least one manic episode, which may be preceded or followed by depressive episodes. Bipolar II involves recurrent depressive episodes with at least one hypomanic episode, but no full manic episodes. Cyclothymic Disorder features chronic fluctuations between hypomanic and depressive symptoms that are less severe than those in Bipolar I or II, lasting for at least two years.