Bipolar disorder, or manic-depressive episode, is a chronic mental illness responsible for mood disorders, most often alternating between states of exaltation and depression.(1)
Bipolar disorder is characterized by reccurent mood disorders (1).
This chronic mental illness was formely called manic-depressive psychosis (1).
In sick people, mood typically oscillates between:
Manic episodes
Exaltation phases, where patients are extremely active, even agitated and sometimes feel euphoric and exalted.
Depressive episodes
Mood decline phases, following a manic phase, where patients may experience great sadness and lose all desire for activity (1).
The remission intervals
Between these manic and depressive episodes, mood can return to normal, or almost normal (1).