Cause

The cause of bipolar disorder is not well understood, although evidence suggests that the disorder runs in families.³ Your living environment and family situation may also play a role in the disorder. Episodes of depression and mania may be caused by a problem with certain brain chemicals called neurotransmitters.

Antidepressant medicines can trigger a manic episode in a person who has bipolar disorder. But this may occur before someone is diagnosed with bipolar disorder, while he or she is seeking treatment for an episode of depression.

Sleep deprivation or substance abuse, including caffeine, can cause a person with bipolar disorder to have a manic episode.