Unmet clinical needs in bipolar disorder.

Bipolar disorder is a complex, chronic condition associated with considerable morbidity and mortality, including a high rate of suicide. Currently available treatment options for bipolar disorder fail to adequately address many of the important needs of bipolar patients. Long-term maintenance therapy with lithium has been shown to prevent further episodes of mania and depression and to decrease the likelihood of suicide. However, many patients stop lithium treatment after only a few weeks, because of either untoward side effects or other factors, such as the belief that they no longer require medication. Even when lithium is taken regularly and at adequate doses, many patients continue to exhibit severe functional disability and also fail to achieve remission. Bipolar depression is also poorly understood and difficult to treat. A number of adjunctive medications are used in combination with lithium, but residual symptoms and recurring episodes of mania and depression remain common. Recently, atypical antipsychotics, such as olanzapine, risperidone, and quetiapine, have been evaluated for the treatment of bipolar disorder. Although considerable research is still needed, preliminary findings suggest that some of these agents may act as mood stabilizers, improving the acute symptoms of mania without inducing depression or rapid cycling. The role of atypical antipsychotics in maintenance therapy for bipolar disorder is currently being evaluated in a number of large clinical trials.