Atypical antipsychotics for bipolar disorder.

Atypical antipsychotic agents have been widely investigated for their efficacy in acute mania. The data to date suggest that olanzapine,risperidone, quetiapine, aripiprazole, and ziprasidone are effective, with no significant differences in antimanic efficacy among these agents. These agents are effective as an alternative to lithium or divalproex as monotherapy or in combination with these mood stabilizers. The data concerning their utility in acute bipolar depression and maintenance treatment of bipolar disorder are limited. The studies to date suggest that olanzapine has modest acute antidepressant properties but probably has efficacy comparable to lithium and divalproex in preventing manic and depressive episodes. Quetiapine seems to have robust antidepressant properties, but these data need to be replicated in further trials before quetiapine can be recommended as a first-line agent for acute bipolar depression. Aripiprazole has shown promise in preventing manic episodes in one 6-month study, but further studies with at least 1-year duration and larger sample sizes are needed before this agent can be recommended as a monotherapy for prophylaxis of bipolar disorder. It is currently unknown if risperidone, aripiprazole, and ziprasidone have any efficacy in treating acute bipolar depression. Similarly, long-term studies are needed to ascertain the role of risperidone, quetiapine, and ziprasidone in the maintenance treatment of bipolar disorder. Overall, the atypical antipsychotic agents as a group represent an effective and relatively safe addition to the armamentarium for the treatment of bipolar disorder.