Bipolar depression is a mood disorder characterized by the alternation of depressive and manic states. The distinguishing characteristic of bipolar depression is the presence of at least one episode of mania. It is also presumed to be a chronic condition because most of the people having manic episodes are likely to have another episode of it in the future. Every person with bipolar depression has a pattern of mood cycles, combining manic episodes with depression, which is unpredictable until the path is found. Bipolar depression usually begins during the teen or early adulthood years and continues throughout one`s lifetime. It`s usually not considered a psychological problem because it happens in episodes, but those who have it may suffer for years without proper treatment.

The exact cause of bipolar depression has not yet been determined. However, most scientists agree that there is no single cause for being bipolar. Scientists believe that stressful factors trigger the first episodes of mania. One reason a person may be bipolar is that the condition is genetic. It appears that many different genes act together in conjunction with a person`s surroundings which create the symptoms associated with bipolar depression. Another cause of bipolar depression could be from the differences in brain structures. MRI tests have shown that those suffering from bipolar depression may have slightly different brain structures than the people who are not effected by the condition. There is also evidence that bipolar depression may be triggered by environmental stresses such as the death of a loved one, the birth of a new baby, or the loss of a job. After a stressful event, a psychological cycle of depression and mania develops in the people with bipolar depression.

Some people do not understand that depression can cause a person to be unable to make simple life decisions. That is why it is important that people with bipolar depression educate their friends, family, and co-workers on the signs of their depressive episodes. Some of the warning signs that you should educate these people on are:

* Lethargy
* Fatigue
* Insomnia
* Lower activity levels
* Loss of interest in activities.

Educating these people puts you in a position to help make sure you take proper action at the start of the episode.

The intensity and frequency of mood swings will vary from person to person. Individuals with bipolar depression may progress to a different category of bipolar depression that gets worse over time of their illness. There are four categories of bipolar depression:

*Bipolar I
*Bipolar II
*Bipolar NOS
*Cyclothemia

The treatment of Bipola I disorder requires one or more mixed or manic episodes. The previous course of the illness may include depressive episodes and hypomania, but the treatment requires only one mixed episode. Bipolar II, the most common form of bipolar depression, is characterized by episodes of disabling depression and hypomania. The diagnosis of Bipolar II requires at least one hypomanic episode. This is used primarily to change from unipolar depression. A patient may be depressed and it is very important to find out if the hypomania has ever caused manic episodes in which the patient was in an uncontrolable state. Bipolar depression is not treated the same way for everybody. Only your doctor can determine the proper cure and exact classification of bipolar episode.

*http://en.wikipedia.org/wiki/Bipolar_disorder
*http://bipolar.about.com/cs/depressive/a/0402_dpsym1.htm
*http://www.thehealthcenter.info/adult-bpd/causes-of-bipolar.htm
*http://www.bipolardepressioninfo.com/
*http://www.ehealthmd.com/library/depressionpregnancy/DPR_glossary.html
*http://www.psychologyinfo.com/depression/bipolar.htm
*http://www.nimh.nih.gov/publicat/depression.cfm
*http://www.medscape.com/viewarticle/473382