Rapid-cycling bipolar I disorder: Course and treatment outcome of a large sample across Europe

ObjectivesTo evaluate the baseline characteristics and follow-up outcomes of rapid-cycling (RC) bipolar I patients in a large, prospective, observational study.MethodsEMBLEM (European Mania in Bipolar Longitudinal Evaluation of Medication) is a long-term prospective observational study of in- and outpatients with an acute mania/mixed episode conducted in 14 European countries.Demographic and clinical variables were collected at baseline, including the presence or absence of DSM-IV rapid-cycling during the past year. Outcome measures included the 5-item Hamilton Depression Rating Scale (HAMD-5) and Young Mania Rating Scale (YMRS) over 12 weeks, as well as the Clinical Global Impressions-Bipolar Disorder Scale (CGI-BP overall, mania and depression) over 12 months.ResultsOf 3684 patients enrolled, 3089 patients provided reliable data to qualify for either RC (N = 535, 17.3%) or non-RC (NRC, N = 2554), according to DSM-IV. RC prevalence varied across countries (p < 0.001). Baseline and 12 week outcomes on the YMRS and HAMD-5, 12 month ratings on the CGI-BP subscales and work impairment at 12 months were significantly different (p < 0.001) between groups, being worse in RC. RC patients were more likely to receive antidepressants and lamotrigine (p < 0.001). Using logistic regression, RC was associated to country (p < 0.001), female sex (p = 0.029), outpatients (p = 0.035), more history of attempted suicide (p < 0.001) and alcohol abuse (p < 0.001).ConclusionsThe EMBLEM results suggest that in naturalistic settings, patients with mania and RC differ from NRC in socio-demographic characteristics, treatment prescriptions and clinical outcome measures with a consistently worse occupational outcome and comorbidities. RC represents a longitudinally severe form of bipolar disorder, with poorly evidence-based diagnostic and therapeutic tools.