The diagnosis of manic-depressive illness is based on the distinctive pattern of symptoms. A doctor determines whether the person is experiencing a manic or depressive episode so that the correct treatment can be given. This condition is known as a mixed bipolar state . Prognosis Manic-depressive illness recurs in nearly all cases. Episodes may sometimes switch from depression to mania, or vice versa, without any period of normal mood in between.
Some people cycle more rapidly through episodes than others.
Up to 15 percent of the people with manic-depressive illness, mostly women, have four or more episodes a year. People who cycle rapidly are more difficult to treat.