Bipolar disorder is a mental illness that causes dramatic shifts in a person’s mood, energy and ability to think clearly. People with bipolar experience high and low moods—known as mania and depression—which differ from the typical ups-and-downs most people experience. The average age-of-onset is about 25, but it can occur in the teens, or more uncommonly, in childhood. The condition affects men and women equally. People with Bipolar disorder have mood episodes that are categorized as manic, hypomanic, or depressive. During an episode, the symptoms last every day for most of the day. Episodes may also last for longer periods, such as several days or weeks. People with bipolar disorders generally have periods of normal mood as well.
There are four distinct types of bipolar disorders:
- Bipolar I Disorder: people with this subtype of illness experience one or more episodes of mania, most have episodes of both mania and depression, though an episode of depression is not necessary for the diagnosis. To be diagnosed with bipolar I, a person’s manic episodes must last at least seven days or be so severe that hospitalization is required.
- Bipolar II Disorder: People with this subset of bipolar disorder experience depressive episodes shifting back and forth with hypomanic episodes, but never a “full” manic episode.
- Cyclothymic Disorder or Cyclothymia: People with this type of illness have chronically unstable mood state with hypomania and mild depression for at least two years. People with cyclothymia may have brief periods of normal mood, but these periods last less than eight weeks.
- Bipolar Disorder, “other specified” and “unspecified” is when a person does not meet the criteria for bipolar I, II or cyclothymia but has still experienced periods of clinically significant abnormal mood elevation.
Scientists have yet to discover a single cause of bipolar disorder. But several contributing factors include:
- Genetics: If a child’s parents or siblings have bipolar disorder, they have an increased chance of developing the disorder. Though this is not absolute as studies of identical twins have found that, even if one twin develops the disorder, the other may not.
- Stress. A stressful event such as a death in the family, an illness, a difficult relationship, divorce, or financial problems may trigger extremes of mood (manic or depressive) episodes.
- Brain structure and function. Brain scans cannot diagnose bipolar disorder; however, scientists are discovering subtle differences in the average sizes or activation of some brain structures in people with bipolar disorder.
However, Bipolar disorders are treatable condition, and people with these disorders can lead full and productive lives with adherence to treatment and therapies. Mental health care providers usually diagnose bipolar disorder based on a person’s symptoms, lifetime history, experiences, and, in some cases, family history. Accurate diagnosis in youth is particularly important.