When someone has severe mood swings from one extreme to another this is technical?

The technical term for when someone has severe mood swings from one extreme to another is "cyclothymia." Cyclothymia is a mental health condition that is characterized by periods of mania or hypomania alternating with periods of depression. During manic or hypomanic episodes, a person may experience elevated mood, increased energy, racing thoughts, decreased need for sleep, and impulsive behavior. During depressive episodes, a person may experience low mood, loss of interest in activities, changes in appetite or sleep, and fatigue. Cyclothymia is a chronic condition, but it can be managed with treatment. Treatment may include medication, therapy, or a combination of both.