Predominant polarity

What is predominant polarity in people with bipolar disorder?

Bipolar disorder is characterised by recurrent episodes of depression and mania, hypomania, or mixed symptoms. Some, but not all, people with bipolar disorder show a predominance of either depression or manic episodes.

A major depressive episode is a period of at least two weeks in which a person has at least five of the following symptoms (including one of the first two): intense sadness or despair; feelings of helplessness, hopelessness or worthlessness; loss of interest in activities once enjoyed; feelings of guilt, restlessness or agitation; sleeping too little or too much; slowed speech or movements; changes in appetite; loss of energy; difficulty concentrating, remembering or making decisions; and/or thoughts of death or suicide.

A manic episode is a period of at least one week when a person is high spirited or irritable in an extreme way most of the day for most days. A manic episode involves changes in normal behaviour such as showing exaggerated self-esteem or grandiosity, less need for sleep, talking more than usual, talking more loudly and quickly, being easily distracted, doing many activities at once, scheduling more events in a day than can be accomplished, embarking on risky behaviour, uncontrollable racing thoughts, and/or quickly changing ideas or topics. These changes in behaviour are significant and clear to friends and family and are severe enough to cause major dysfunction.

A hypomanic episode is similar to a manic episode but the symptoms are less severe and need only last four days in a row. Hypomanic symptoms do not lead to the major problems that mania often causes, and the person is still able to function.

What is the evidence for predominant polarity in people with bipolar disorder?

Moderate to high quality evidence suggests mania and depression predominance is similar in studies assessing symptoms retrospectively. However, mania episodes were less prevalent than depression episodes when episodes are measured prospectively over the course of bipolar disorder.

Factors associated with depression predominance are; type II bipolar disorder, melancholia symptoms, a depressive onset of illness, suicide attempts, mixed episodes, delayed diagnosis of bipolar disorder, and being married. Factors associated with mania predominance are; type I bipolar disorder, a mania onset of illness, onset of illness with psychotic features, younger onset of illness, and substance use.

September 2021

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Last updated at: 2:01 pm, 15th February 2022
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