Question: What is the difference between bipolar I disorder and bipolar II disorder? Need Assignment Help? O Bipolar | disorder lasts for a relatively short time. Bipolar Il lasts for years. O Bipolar | disorder may include manic and depressive episodes. Bipolar II disorder involves hypomanic episodes and depressive episodes. O Bipolar | disorder involves depersonalization/derealization. Bipolar II disorder does not involve either of these. O Bipolar | involves depressive episodes only. Bipolar II involves hypomanic and depressive episodes.