How long a person remains depressed or manic varies and usually ranges from a few days to several months.  The intervals between episodes range from days to months to years.  An individual will eventually recover from depression or mania without treatment but usually recovers more quickly with treatment.  Before 1940 the average duration of a depressive episode was four months, of a manic episode about three months,  Some periods of depression lasted as long as a year or more.  After 1960, in response to the use of new medications such as Lithium, episodes tended to be shorter.

Some people discover a predictable pattern, others do not.  in a 1973 study of 400 patients who have bipolar disorder only two did not have a recurrence.  Other studies reveal that before the introduction of the drug Lithium, about 75% of manic patients had more than one episode in their lifetime.

The first episode of bipolar disorder usually occurs in young adulthood.  The occurrence of manic episodes in people over 50 is often indicative of some other medical illness of of some effects of drugs, alcohol or steroids.

Men and women are equally susceptible to this disease.  1 to 2 percent of the population is expected to develop bipolar disorder in a lifetime.  The risk increases among first degree or immediate relatives where there is a 15 percent chance of developing bipolar disorder.

Manic depressive illness affects all social groups, including people with high positions in society.  To mention but a few historical figures who have had this illness, Abraham Lincoln, Theodore Roosevelt and Winston Churchill were all reported to have experience manic episodes followed by black periods of depression.  Other well know people with bipolar disorder, both in the past and present include the authors F. Scott Fitzgerald and Ernest Hemmingway, and actresses Patty Duke, and Vivien Leigh (Scarlett O'Hara in "Gone With The Wind").

Researchers have not identified a single cause of bipolar disorder.  Genetic investigations have shown that biological factors play a major role in producing the illness.  Often bipolar disorder tends to concentrate in families.  Currently researchers are looking for genetic markers that would identify people at risk.  It seem to be "just a matter of time" before they find such markers. Much research has also focused on such physiological aspects as brain chemistry, the endocrine and hormonal systems.  Also there have been studies on stressful events to biological changes.  An excellent detailed account of such studies can be found in chapter 4 of the book "Overcoming Depression" by Papolos, pages 55-84

Unfortunately, only one in three people suffering from a mood disorder (this includes depression and bipolar disorder) seeks help.  Only one in ten seeks help from a psychiatrist who is specifically trained to diagnose such illnesses and treat them medically.  This may be due to a person's desire to "go it alone", or to a lack of knowledge and understanding of what it is that is going on inside of him or her.

Denial of the disease is not uncommon, especially during a manic episode.  Some patients are reluctant to give up the experience of the mania.  The increased energy, euphoria, heightened self-esteem and ability to focus may be very desirable and enjoyable.  Some patients only remember this part of the experience while minimizing or denying the subsequent devastating features of full-blown mania or the extended demoralization of a depressive episode.

Side effects of medication and other demands for long-term treatment may also be burdensome.  These need to be discussed carefully with a physician.  Many side effects can be corrected or reduced with careful attention to dosing, scheduling and preparation.

In any case, many people tragically deny themselves the substantial relief from crippling symptoms that medical treatment could give them.