Current concepts in rapid cycling bipolar disorder.

The rapid-cycling variant of bipolar disorder (RCBD) has been variably defined, with episode frequencies ranging from several per day to a minimum of four per year. It is diagnosed disproportionately in women with bipolar II disorder. Its time of onset may be in childhood, adolescence, or adulthood. It appears to be treatment refractory, but controlled trials are lacking. Concurrent treatment with lithium and an antiepileptic drug is considered the current mainstay of treatment, and antidepressants are discouraged. Controlled trials in homogeneous cohorts of RCBD patients are needed. Preliminary data suggest that two or more mood stabilizers are required for adequate control.