There are several types of bipolar disorder; all involve episodes of depression and mania to a degree. Bipolar disorder is a lifelong illness. Episodes of mania and depression eventually can occur again if you don't get treatment.Many people sometimes continue to have symptoms, even after getting treatment for their bipolar disorder. Here are the types of bipolar disorder 1  : Bipolar I disorder involves periods of severe mood episodes from mania to depression.2  Bipolar II disorder is a milder form of mood elevation, involving milder episodes of hypomania that alternate with periods of severe depression.here are several types of bipolar disorder; all involve episodes of depression and mania to a degree. Bipolar disorder is a lifelong illness. Episodes of mania and depression eventually can occur again if you don't get treatment.