Maintenance therapy in bipolar disorder - more data needed

US researchers examine the available evidence for maintenance therapies in bipolar disorder, concluding that further data on combining therapies is needed to guide clinical treatment.Most research has focused on management of acute bipolar episodes. However, prevention of these acute episodes through maintenance phase of treatment is crucial to improve the poor long-term outcomes associated with this disorder.The use of lithium as maintenance therapy in bipolar disorder is supported by a large body of evidence, although a lack of adequate response in 20-40% of patients, undesirable side effects, a narrow therapeutic index and risk of toxicity mean that alternatives are required.A literature search revealed numerous studies focusing on lithium, many of which showed it to be superior to placebo in preventing both manic and depressive relapse. Some studies comparing carbamazepine and lithium in prevention of bipolar relapse found them to be of equivalent efficacy while others found lithium to be superior. Other studies have suggested that carbamazepine is an effective alternative to lithium in maintenance treatment of bipolar disorder but that its prophylactic efficacy may decline over time.The general consensus is that carbamazepine is inferior to lithium in maintenance treatment of bipolar disorder, the researchers state.Studies have suggested that valproate is at least as effective as lithium in bipolar prophylaxis and is better tolerated. However, a relative lack of randomised controlled studies means that the true efficacy of valproate remains uncertain.There are now substantial data regarding the use of lamotrigine in bipolar prophylaxis, with some studies supporting it use as a mood stabiliser, perhaps complementary to lithium.Other research supports the use of lamotrigine for mood episodes below baseline in bipolar I patients. Research also suggests that lamotrigine may be useful for rapid-cycling bipolar II patients.Recent research evaluating the use of olanzapine in bipolar prophylaxis, suggests that it is effective as monotherapy and as an addition to lithium. The researchers conclude that the available data particularly support the use of lithium, lamotrigine and olanzapine monotherapies for relapse prevention in bipolar I disorder."Since the majority of patients with bipolar disorder require, or are placed on, some form of combination long-term medication therapy, there remains a need to obtain further data on the various permutations possible in order to more accurately and safely guide clinical treatment."Reference...