Sustained remission with lamotrigine augmentation or monotherapy in female resistant depressives with mixed cyclothymic-dysthymic temperament

Background: The treatment of bipolar depression remains problematic. Lamotrigine has been shown in randomized controlled studies to be efficacious in preventing bipolar depression and rapid cycling states. Methods: Twenty-four women with cyclothymic temperament and refractory depression were recruited from four outpatient sites (three primary care and one psychiatric) and treated with lamotrigine in a naturalistic, open-label study. Temperament was determined by responses on the TEMP-A self-rating scale. Eighteen (75%) of these cyclothymic patients also scored high on the depressive temperament. Eighteen (75%) met DSM-IV criteria for bipolar II disorder. In two thirds of the cases, lamotrigine was add-on therapy to an antidepressant. Response to therapy was assessed using the DSM-IV Global Assessment of Functioning (GAF). Limitations: This study was naturalistic in design, without controls or blinds. Results: Of the 23 patients who remained in the study, 16 (70%) had significant, sustained responses. Of these 16, 12 (75% of responders, 52% of the total) had remissions (GAF>80) sustained longer than 12 months. Robust, sustained responses to lamotrigine monotherapy were seen in 4 patients (17%). Seven patients (30%) received no apparent benefit from lamotrigine. Conclusions: Lamotrigine induced prolonged illness remissions in a substantial number of female patients whose symptoms were both complex and refractory. Most manifested high scores on the cyclothymic and depressive temperaments, and prior refractoriness to multiple antidepressant and antidepressant/mood stabilizer combinations, before remitting with lamotrigine augmentation or monotherapy.