Risk factors for rapid cycling in bipolar disorder.

OBJECTIVES

The aim of this study was to investigate the clinical factors associated with the development of rapid cycling, as well as to elucidate the role of antidepressants.

METHODS

The present study (NCT01503489) is a prospective, naturalistic cohort study conducted in a sample of 289 patients diagnosed with bipolar disorder followed and treated for up to 14 years. The patients were divided into two groups on the basis of the development of a rapid cycling course (n = 48) or no development of such a course (n = 241), and compared regarding sociodemographic, clinical, and outcome variables.

RESULTS

Among the 289 patients, 48 (16.6%) developed a rapid cycling course during the follow-up. Several differences were found between the two groups, but after performing Cox regression analysis, only atypical depressive symptoms (p = 0.001), age at onset (p = 0.015), and number of suicide attempts (p = 0.030) persisted as significantly associated with the development of a rapid cycling course.

CONCLUSIONS

The development of rapid cycling during the course of bipolar disorder is associated with a tendency to chronicity, with a poorer outcome, and with atypical depressive symptomatology. Our study also suggests that the development of rapid cycling is associated with a higher use of antidepressants.