how long does a manic episode last if untreated
1 If you have had at least one high or manic episode, which has lasted for longer than one week. 2  You may only have manic episodes, although most people with Bipolar I also have periods of depression. 3  Untreated, a manic episode will generally last 3 to 6 months.sychotic symptoms. If an episode of mania or depression becomes very severe, you may develop psychotic symptoms. 1  In a manic episode-these will tend to be grandiose beliefs about yourself-that you are on an important mission or that you have special powers and abilities.