Authors: Calabrese JR, et al.; for the Lamictal 614 Study Group. Title: A double blind, placebo-controlled prophylaxis study of lamotrigine in rapid-cycling bipolar disorder. Reference: J Clin Psychiatry 2000;61:841-50. Purpose: To examine lamotrigine as maintenance monotherapy for rapid-cycling bipolar disorder. Study design: Randomized, double-blinded, parallel-group, placebo-controlled, multicenter study. Initial open-label phase of 4–8 weeks. Follow up: 6 months. Patients: 182 patients with bipolar I and II disorder met stabilization criteria from the open-label phase and continued to the maintenance-treatment phase (93 lamotrigine, 89 placebo). Treatment: In the open-label phase, lamotrigine was titrated to 100–300 mg/day and added to current therapy, with gradual withdrawal of concomitant drugs. Stabilized patients were randomly assigned to lamotrigine 100–500 mg/day or placebo. Results: There was a 6-week difference in overall survival time favoring lamotrigine over placebo. This was driven largely by the efficacy of lamotrigine in bipolar II patients. 41% of lamotrigine-treated patients were stable without relapse for 6 months of monotherapy, compared with 26% of placebo-treated patients (a significant difference). There was no significant difference between groups in the time to additional pharmacotherapy. Lamotrigine was well tolerated.