Rapid Cycling in Bipolar Disorders: Symptoms, Background and Treatment Recommendations

Rapid cycling bipolar disorder is encountered frequently in clinical practice with a lifetime prevalence of up to 31 %. Besides its association with greater illness severity, increased suicide and comorbidity rates, rapid cycling bipolar disorder has been closely associated with a longer and more complicated course of disease and inadequate treatment response compared to non-rapid cycling bipolar disorder. However rapid cycling does not serve as a stable characteristic of bipolar disorder, though its prevalence increases with illness duration. Female gender, hypothyreoidism and antidepressant medications have been suggested as correlates of rapid cycling bipolar disorder; however, the interaction amongst these factors make an interpretation of their causal relations difficult. Only very few data are available from randomized clinical trials that investigated the therapeutic options of rapid cycling bipolar disorder. Based on these trials, the therapeutic outcome of lithium is similar to that of the class of anticonvulsants. Positive treatment outcome reported for atypical neuroleptics is often based on pharmaceutical company-financed, placebo-controlled RCTS. Altogether independent prospective RCTs and head-to-head comparisons are lacking that can provide sufficient information on treatment response. In addition, the role of antidepressant treatment in the course and phase acceleration of bipolar disorder remains insufficiently understood. However, in the light of present empirical evidence, the use of antidepressant medication in the treatment of rapid cycling bipolar disorder has to be looked at highly critically.