Sociodemographic, clinical and treatment characteristics of current rapid-cycling bipolar disorder: a multicenter Chinese study

Rapid cycling bipolar disorder (RCBD), characterized by four or more episodes per year, is a complex subtype of bipolar disorder (BD) with poorly understood characteristics. This multicenter, observational, longitudinal cohort study enrolled 520 BD patients across seven psychiatric institutions in China from January 2013 to January 2014. Participants were divided into RCBD and non-RCBD (NRCBD) groups based on the frequency of mood episodes in the preceding year. Data collection utilized a standardized form, supplemented by a medical record review, focusing on sociodemographic, clinical, and treatment characteristics. Statistical analysis involved independent samples t-tests, Kruskal–Wallis H tests, Chi-square or Fisher's exact tests, with Bonferroni correction applied to account for multiple comparisons, and multivariable logistic regression to identify characteristics associated with RCBD. Among the BD cohort, 9.4% were identified as current RCBD. Compared to NRCBD, RCBD patients had a shorter duration from the first psychiatric consultation to the diagnosis of BD, a reduced duration of their longest period of euthymia, a lower proportion of lifetime hospitalization history due to BD, and less use of electroconvulsive therapy (ECT) within the last 12 months. Additionally, they presented higher baseline scores on the Mood Disorder Questionnaire (MDQ) and the Brief 16-item Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR16). However, after applying the Bonferroni correction, these differences were not statistically significant. Multivariable logistic regression analysis identified three factors that were independently associated with RCBD: time from first psychiatric consultation to BD diagnosis (Odds Ratio [OR] = 0.512, P = 0.0416), lifetime hospitalization history due to BD (OR = 0.516, P = 0.0476), and ECT treatment within the past 12 months (OR = 0.293, P = 0.0472). This study revealed that the duration from first psychiatric consultation to BD diagnosis, lifetime hospitalization history due to BD, and ECT treatment in the past year were associated with RCBD. Recognizing these factors could contribute to enhance the early identification and clinical outcomes of RCBD. Trial Registration Number Registry ClinicalTrials.gov NCT01770704. Date of Registration: First posted on January 18, 2013.