There are several different types of
bipolar disorder. Each is based on whether the person has more trouble with depression or mania and how often mood cycles
occur.1
Bipolar I
Considered the classic form of the illness, bipolar I causes
recurrent episodes of mania and depression. The depression may last for a short
time or for months. The person may then go back to feeling normal for a time, or
he or she may go right into a manic episode.
Bipolar II
People who have bipolar II experience depression just as in bipolar
I. But the episodes of mania are less severe (hypomania). People with bipolar II have more depressive than hypomanic
episodes.
Rapid-cycling bipolar disorder
People with rapid-cycling bipolar disorder experience at least four
episodes of depression, mania, or both within a 12-month period. They may go
directly from an episode of depression to an episode of mania, or they may have
a short time lapse between the two moods. The mood swings are the same as with
other types of bipolar, but the frequency of mood swings distinguishes
rapid-cycling bipolar disorder from the other subtypes.
Some people with bipolar disorder may have mixed symptoms, in which
depression and mania occur together. Symptoms include sadness, euphoria, and
irritability. Other symptoms can include agitation, lack of sleep, appetite
changes and, possibly, thoughts of suicide. This can make the disorder
challenging to treat and very frustrating to live with.