Bipolar I and Bipolar II are two different forms of bipolar affective disorder. You will experience two similar stages or episodes with this bipolar, which are depression and the neutral mood. The episodes experienced by patients having bipolar I am depression and mania, while the episodes that are usually experienced by patients suffering from bipolar II are depression and hypomania.
The patient might just feel normal sometimes, too, without feeling any of those episodes. Mania refers to a state of elevated and abnormal emotion or energy mood. Whereas, hypomania refers to a lower degree or state of mania. Medication is used in the case of mania, while it is not needed for hypomania.
Those with bipolar, I might end up having a crippled lifestyle, while those with bipolar II can still function well. Psychosis is experienced in patients with bipolar I during the manic episode. This same psychosis is experienced by patients with bipolar II during the stage of depression.