With bipolar disorder, you alternate between episodes of depression and mania. In between, you may return completely to normal or have some remaining symptoms. The extreme mood changes may come on suddenly or appear more slowly.

During a manic episode, you may be abnormally happy, energetic, or very irritable for a week or more. Initially, you may feel incredibly productive or creative. You may feel powerful and seductive and think there is nothing you can't accomplish. But as a manic episode progresses, you may behave wildly and irresponsibly, spending a lot of money, getting involved in dangerous activities, and sleeping very little. You may also have a hard time functioning in your job and relationships.

After a manic episode, you may return to normal, or your mood may swing in the opposite direction and you may feel useless, hopeless, and extremely sad. When you are depressed, you may have trouble concentrating, remembering, and making decisions; you may have changes in your eating and sleeping habits; and you may lose interest in things you once enjoyed. Some people become suicidal or harm themselves during episodes of depression. Some feel as if they can't move, care, or think.

Men tend to have more manic episodes, while women have more episodes of depression.⁶

Initially, stress may trigger depression or mania. But, as the illness progresses, mood swings may not be caused by any specific event. Without treatment, your bipolar disorder may get worse, causing you to move more often between mania and depression.