Bipolar disorder is a mental health condition involving significant shifts in mood, energy, and activity levels that can affect a person’s ability to carry out daily tasks. As a spectrum disorder, symptoms and their severity differ greatly from person to person, ranging from intense highs to profound lows.
A formal diagnosis from a qualified healthcare professional is necessary to understand the condition. Professionals identify distinct subtypes based on the character and severity of the mood episodes a person experiences, which is a necessary step for creating an effective management plan.
Bipolar I Disorder
The defining feature of Bipolar I disorder is the experience of at least one manic episode. A manic episode is a distinct period of an abnormally elevated or irritable mood, accompanied by a significant increase in energy. To be classified as a manic episode, this state must last for at least one week and be present for most of the day, nearly every day, unless hospitalization becomes necessary.
During a manic episode, an individual might exhibit a range of symptoms, including:
- An inflated sense of self-esteem or grandiosity
- A decreased need for sleep, feeling rested after only a few hours
- Being much more talkative than usual
- Racing thoughts or a flight of ideas
- Being easily distracted by unimportant external stimuli
This period of mania often leads to an increase in goal-directed activity, which can be social, work-related, or sexual in nature. However, it can also manifest as psychomotor agitation, which is purposeless and non-goal-directed. A common feature is excessive involvement in activities that have a high potential for painful consequences, such as unrestrained buying sprees or foolish business investments.
A manic episode causes marked impairment in social or occupational functioning and often necessitates hospitalization to prevent harm to the individual or others. While major depressive episodes are common in Bipolar I, they are not required for diagnosis if a full manic episode has occurred.
Bipolar II Disorder
A diagnosis of Bipolar II disorder requires that an individual has experienced at least one hypomanic episode and at least one major depressive episode. There must be no history of a full manic episode. The presence of both the “high” of hypomania and the “low” of a major depressive episode defines this subtype.
A hypomanic episode shares many symptoms with a manic episode, such as elevated mood and increased energy, but it is less severe. A hypomanic episode must last for at least four consecutive days, a shorter duration than the one-week requirement for mania.
Unlike a manic episode, a hypomanic episode is not severe enough to cause major problems in social or work functioning or require hospitalization. While the change in mood and functioning is observable to others, some individuals may find their hypomanic periods to be productive.
For many people with Bipolar II, the major depressive episodes are the most challenging aspect of the illness. These periods of low mood, loss of interest or pleasure, and fatigue can be recurrent and debilitating. It is often the distress from the depressive episodes that leads individuals with Bipolar II to seek professional help.
Cyclothymic Disorder
Cyclothymic Disorder is characterized as a chronic form of bipolar disorder with milder mood fluctuations. Individuals with this condition experience numerous periods with hypomanic symptoms and periods with depressive symptoms over an extended time. For an adult to be diagnosed, these symptoms must be present for at least two years, while for children and adolescents, the duration is at least one year.
The symptoms experienced in cyclothymic disorder are not severe enough to meet the full diagnostic criteria for a hypomanic or major depressive episode. Instead, the condition is defined by a persistent instability of mood.
The individual is not symptom-free for more than two months at a time. This persistent pattern of fluctuation can lead to an uneven work or school history and strained interpersonal relationships.
Although the symptoms are milder, the chronic nature of cyclothymic disorder can cause distress and functional impairment. A notable percentage of individuals with cyclothymia may later develop a more severe form of bipolar disorder. The early onset and pervasive course of the disorder can sometimes make it difficult to distinguish from personality disorders.
Other Bipolar Presentations
When an individual’s symptoms indicate a bipolar disorder but do not fit the criteria for Bipolar I, II, or Cyclothymic Disorder, clinicians use other diagnostic categories. These categories acknowledge that the person is experiencing distress or impairment from bipolar symptoms that require attention.
One such category is “Other Specified Bipolar and Related Disorder.” This diagnosis is used when a clinician communicates the specific reason the presentation does not meet the criteria for another bipolar disorder. For example, a person might experience episodes of hypomania that are shorter than the required four days, or have hypomanic episodes with an insufficient number of symptoms.
Another category is “Unspecified Bipolar and Related Disorder.” This diagnosis is used when there is not enough information to make a more specific diagnosis, such as in an emergency room setting. The clinician may not have the opportunity to conduct a full assessment but can still indicate that a bipolar-related condition is present.