Can be introduced at any phase of bipolar disorder to prevent a depressive episode.

Results from two large clinical trials – one in recently depressed bipolar patients and one in recently manic patients – showed that the prophylactic efficacy of Lamictal is not dependent on the polarity of the most recent mood episode. There is accumulating evidence of the efficacy of Lamictal, administered either acutely or long term, in controlling the depressive symptoms of bipolar disorder. Lamictal has a clear protective effect against depression. At the very least, it has minor efficacy against mania, without detrimental effect.