Bipolar disorder is a severe, affective illness which causes a person to alternate between episodes of pathologically elevated mood (mania) and depression ? in between these episodes the mood is normal. The length and intervals between the episodes are highly variable among the ill, as are the severity which is divided into two major subgroups: bipolar I and II. Bipolar I disorder is the most severe because of the patient?s inability to realize that he or she is currently in a manic phase, in the case of bipolar II disorder, the patient is aware that he or she has an abnormally raised mood, a state which is called hypomanic state instead of manic.