Bipolar disorder is the new name for what used to be called manic depression. It better describes the exaggerated swings of mood from one extreme to another characteristic of this illness. Some only experience attacks of mania, without the subsequent steep slide into depression.
Episodes can range from mild to severe.
The less severe form of elevated mood, or 'high', is called 'hypomania'. Mania' is the word used to describe the most severe form of the disorder. They describe the experience as feeling on top of the world and invincible. Rapid thinking and speech - thoughts are more rapid than usual, this can lead to sufferers speaking very quickly and jumping from subject to subject. Lack of inhibitions - this can be the result of the person's reduced ability to foresee the consequences of their actions.