What is mood cycling?
Bipolar disorder is characterised by recurrent episodes of depression and mania or hypomania. The duration of mood episodes varies between patients, from several days to several months, with usually a period of remission in between. The frequency of mood changes (cycling) also varies between patients, with four or more episodes per year classified as rapid cycling.
A 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 mood cycling?
High quality evidence shows there is less treatment response in people with continuous cycling bipolar disorder compared to people without continuous cycling.
Moderate to low quality evidence suggests the mean annual prevalence of rapid cycling in people with bipolar disorder is around 18%, and the lifetime prevalence is around 31%, indicating rapid cycling is a transitory phenomenon. Factors associated with rapid cycling include; longer course of illness, earlier age at onset, substance use, and suicidality.
Moderate quality evidence suggests manic episodes peak during spring/summer and, to a lesser extent, in autumn. Depressive episodes peak in early winter and, to a lesser extent, in summer. Mixed episodes peak in early spring or mid/late summer. Moderate to low quality evidence suggests there are menstrual cycle-related mood changes in 44% to 68% of women with bipolar disorder. 25% to 77% of women with bipolar disorder met the criteria for premenstrual syndrome, and 15% to 27% met the criteria for premenstrual dysphoric disorder.
Green - Topic summary is available.
Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.