Sunday, November 16, 2008

BIPOLAR DISORDER

Bipolar disorder,
also known as manic-depressive illness, is a psychiatric disease characterized by periods of abnormally elevated moods, often followed by episodes of depression. An individual with manic-depressive illness has episodes of mania characterized by an abnormally elevated mood, sleeplessness, racing thoughts, and pressured speech. In severe cases, thoughts become increasingly chaotic, and may become completely removed from reality. Without treatment, the disorder often has disastrous consequences: during manic episodes, peoples' actions may cause them to lose jobs, destroy relationships, go into debt, and even put themselves into dangerous situations. Hospitalization is sometimes required to prevent such consequences or suicide. Cycles of manic and depressive episodes may occur occasionally or several times a year depending on the individual. Most people feel no symptoms between episodes. If untreated, episodes generally become progressively more frequent and severe. Medications and psychotherapy help to stabilize moods and alleviate symptoms. Bipolar disorder affects about 1% of the adult population. Manic depressive illness is recognized worldwide, and is about evenly distributed between men and women. The disorder typically begins in adolescence or early adulthood.

Causes ............. Manic-depressive illness is known to have a strong genetic basis. Bipolar disorder tends to run in families. More than two-thirds of people with the disorder have a close relative with it or with depression. Twin studies also support the genetic basis of the disorder: both members of a set of identical twins are more likely to have depression (33%-90%) than both members of a set of non-identical twins (5%-25%). Although the exact pattern of transmission remains unknown, some genes have recently been identified that are associated with the disease. It appears that multiple genes are involved, a particular mix of which determines the various features of the illness.

Symptoms.............The manic phase of the illness is characterized by a persistent, abnormally elevated mood [Table 1]. Manic episodes tend to arise over a period of days to weeks. The person often seems to be euphoric, but may instead be intensely agitated. Affected individuals usually experience increased energy, with rapid, loud speech, a reduced need for sleep, and distractibility. The person may afterwards describe racing thoughts or ideas that seemed to take flight. During an episode, he or she may feel that even mundane conversations or ordinary details are intensely interesting. The person may make wild plans and take action on them, such as flying out of the country without adequate preparation, making crazy business investments, or going on extensive shopping sprees to the point of debt. The manic individual typically does not realize that thoughts are irrational, and will deny having a problem. In milder cases or early in the episode, activities may be channeled productively into work or creative pursuits. Oftentimes, however, thoughts progress too rapidly, irrationally, and chaotically to be constructive. If untreated, an episode may last for weeks, or even as long as a year. A depressive phase usually follows the manic episode. When present, symptoms are identical to those of unipolar depression. Depressive episodes may follow the manic episode. During a depressive episode, an overwhelmingly sad mood and profound loss of interest in activities takes over. Physical symptoms, such as changes in sleep and eating habits, are common, and the person may have thoughts of death and suicide. Severe states of mania or depression may involve psychotic symptoms in which the individual is unable to separate fantasy from reality. During manic or depressive episodes, a person may experience delusions (for example, beliefs of communicating with aliens or of having god-like powers) or hallucinations (such as hearing imaginary voices or seeing things that aren't there). Psychotic symptoms often provoke anxiety, and may involve fears of being harmed by others. When such symptoms are present, the disease resembles schizophrenia, and may respond to medications used for treating schizophrenia. The frequency and duration of episodes of mania and depression vary among individuals. The manic and depressive episodes of each cycle typically occur within three months of each other. Between these cycles, most people feel well, and will have no symptoms. Some people experience many cycles of mania and depression each year. People with rapid cycles should be checked carefully for underlying thyroid disease or a drug-induced cause.