Bipolar disorder is characterized by a manic episode followed by either a depressive or hypomanic episodes.
People caught in a depressive episode experience at least two weeks of feeling sad, empty, or hopeless. They lose interest in activities they once enjoyed and may lose weight, have difficulty sleeping, or may spend more than half the day in bed. They may feel both exhausted and agitated, worthless, excessively guilty, and lose their ability to concentrate or make simple decisions. And most dangerously, they may lose their will to live, and even seek ways to end their life.
People in the midst of a manic episode experience at least a week of persistently elevated or irritable mood. They may be expansive — seeing themselves as possessing special powers or abilities. They may shout at or start arguments with people they don’t know. They may lose their need for sleep — feeling fully rested after only 3 hours. They may be so talkative that people have trouble interrupting them. They may experience their thoughts as racing, so much so that they are incapable of keeping their mind focused on one thing. They may be so active that friends and family are worried about them. And they may be so impulsive and reckless that they put their physical and financial health at risk.
Depressive and manic episodes can vary in frequency, intensity, and duration. Bipolar I disorder is characterized by intense manic episodes. At their worst, people may require hospitalization. Bipolar II disorder is characterized by more brief (4 days), less intense episodes of mania, which is called hypomania.