Bipolar disorder is a severe mood disorder that usually begins in late adolescence or early adulthood. Most researchers agree that the disorder has no one specific cause, but multiple factors act together to cause bipolar disorder. The most common causes purposed are heredity and brain abnormalities. According to studies cited by the National Institute of Mental Health, children with a parent or sibling with bipolar disorder are four to six times more likely to develop the disorder. Identical twin studies, however, show that environment must play a significant role as well. Results of numerous studies found that on average only 60 percent of identical twins both had bipolar disorder. Brain scans have also shown that people with bipolar disorder may have structural differences when compared to a normal brain.
Bipolar I
People who have bipolar I disorder have experienced one or more manic or mixed episodes and usually one or more major depressive episodes. This is often considered the more severe form of bipolar disorder because the extreme mood elevation can include psychotic symptoms and frequent risk-taking behavior such as drug use and unprotected sex. People experiencing a manic episode may suddenly have an inflated self-esteem, a decreased need for sleep, an increase in goal-directed activities and excessive involvement in pleasurable but potentially dangerous activities.
Manic symptoms can be contrasted with a mixed episode in a manic episode's lack of major depressive symptoms. People having a mixed episode are often agitated, having suicidal thoughts, insomnia and an irregular appetite, among other depression symptoms. Both manic and mixed episodes significantly affect social and occupational functioning and may require hospitalization.
A major depressive episode may include recurrent thoughts of death, a depressed mood and little interest in pleasurable activities.
People with bipolar I can cycle back in forth between a manic or mixed episode and a major depressive episode within months, hours or days. Those that shift within hours or a few days are often referred to as rapid cyclers. Rapid cycling usually develops much later in the course of the disorder. People with bipolar I can also experience periods of remission between cycles, which usually happens during the beginning of the disorder.
Bipolar II
Those with bipolar II disorder experience a milder form of mania called hypomania. Though a hypomanic episode has the same symptoms as a manic episode, symptoms are not severe enough to impair social and occupation activities or warrant hospitalization. People with bipolar II have also had one or more periods of major depression. As in bipolar I, some people with the disorder rapidly cycle through hypomania and depression. They can also experience periods of remission. If a manic or mixed episode is experienced, the person would then be classified as bipolar I.
Cyclothymic Disorder
Cyclothymic disorder is an even milder form of bipolar disorder in which symptoms never reach manic, mixed or major depressive episodes. People with cyclothymic disorder, however, experience periods of hypomania and depression. Like other bipolar disorders, cyclothymia occurs equally in men and women. Some studies suggest that nearly 50 percent of people with cyclothymia also have a substance abuse problem. Cyclothymia often goes untreated or undiagnosed because people often think their symptoms are not severe enough to warrant treatment or it is misdiagnosed. Still others may like their mood elevations as they can be very productive periods.
References
- Diagnostic and Statistical Manual of Mental Disorders 4th Edition Text Revision, 2000
- Child Psychopathology 2nd Edition, 2003
- Oxford Textbook of Psychopathology, 1999
