The evolution of antiepileptic drugs for mood stabilization and their main mechanisms of action.

Although much progress has been made in successfully treating bipolar disorder, there is increasing awareness of the limitations of traditional treatment regimes, such as lithium or antipsychotics and the possible beneficial use of antiepileptic drugs. After the first generation of antiepileptic drugs such as phenytoin and clonazepam, the second generation is comprised of the frequently-used substances carbamazepine/oxcarbazepine and valproate. Lamotrigine, gabapentin, tiagabine, levetiracetam, zonisamide and topiramate will represent the third generation 5 years from now. Drugs such as retigabine might represent the next generation. However, the efficacy of antiepileptic drugs investigated in the treatment of bipolar disorder differs and most promising effects are seen in combination therapy with mood stabilizers. The authors review the main mechanisms of action of these drugs which may, in turn, improve our understanding of the pathophysiology of bipolar disorder.