Lamotrigine: a depression mood stabiliser.

Depression mood stabilisers, which stabilise mood from below the mood baseline (euthymia) without inducing switch into mania or episode acceleration, are urgently needed for the effective treatment of bipolar depression. The anticonvulsant lamotrigine, recently approved as maintenance therapy for bipolar depression, has undergone evaluation as acute and maintenance therapy for bipolar disorder in several controlled clinical trials. Data from these trials suggest that lamotrigine is effective in the treatment and prevention of bipolar depression without destabilising mood. Although the majority of evidence comes from studies in patients with bipolar I disorder, a recent naturalistic study suggests that these observations may also extend to patients with bipolar II disorder. Lamotrigine may therefore fulfil the unmet need for an effective depression mood stabiliser.