Mood Disorders Society of Canada is pleased to present this third edition of What is Bipolar Disorder

For people with bipolar disorder, these normal emotions can become a roller coaster ride of wild highs and devastating lows. Moods are driven, not by the events of life, but by a force of their own. Bipolar disorder (previously called manic-depressive illness) is a medical condition that involves changes in brain function leading to dramatic mood swings. These mood swings can be so severe that they impair normal functioning at work, at school, and in relationships.