Verified answer

There is some genetic base for bi-polar disorder. If you have a parent with Bipolar disorder you have a higher chance of developing it if thrown into a stressful situation. You can look it up in any abnormal psych text book on line or in the library. There is a chemical imbalance of a few different substances in the brain.

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.

its a chemical imbalance in the brain. Read about it on a few medical websites like webmd.