Which of the following anticonvulsants is used for bipolar disorder?

Lamotrigine is recognized for its efficacy in treating bipolar disorder, particularly in stabilizing mood and preventing depressive episodes. It functions by modulating glutamate release and preventing excitatory neurotransmitter surges, which can help in the management of mood swings associated with bipolar disorder. Clinically, it is often used as a maintenance treatment in bipolar disorder, especially for individuals who experience more depressive episodes than manic episodes.

In contrast, gabapentin, phenytoin, and topiramate, while they are anticonvulsants, do not have the same established role in managing bipolar disorder. Gabapentin is usually utilized for neuropathic pain and anxiety disorders, and phenytoin primarily manages seizures. Topiramate can have mood-stabilizing effects; however, it is not a first-line treatment for bipolar disorder compared to lamotrigine. Thus, lamotrigine stands out as the most appropriate choice in this context for its specific application in bipolar disorder management.