Atypical antipsychotics for the treatment of bipolar disorder: more shadows than lights.

Atypical antipsychotics are utilised more frequently for the treatment of bipolar disorder than first-generation antipsychotics because of their improved neurological tolerability. Furthermore, recent studies suggest that psychiatric outcomes are improved in patients treated with atypical agents. The aim of this article is to review the studies evaluating the effectiveness of atypical antipsychotics in treating acute bipolar episodes (bipolar mania, bipolar depression and mixed episodes), as well as those investigating the effectiveness of atypical antipsychotics as maintenance treatment for the disorder. Because of several relevant methodological limitations affecting the vast majority of clinical trials, evidence-based information about the effectiveness of atypical antipsychotics in treating bipolar disorder is somewhat discouraging. Moreover, data indicating effectiveness in managing the acute manic phase and in long-term maintenance treatment are quantitatively robust only for olanzapine. However, olanzapine seems to have no advantages in terms of tolerability and therapy compliance when compared with classical mood stabilisers or first-generation antipsychotics. In addition, only a few studies have investigated the efficacy of atypical antipsychotics for treating bipolar depression. Hence, information regarding the effectiveness of such medications in treating this specific phase of bipolar disorder should be considered as still preliminary. Given this situation, further independent and well-designed studies are urgently needed before definitive conclusions on the effectiveness of most atypical antipsychotics in the different clinical situations characterising the natural course of bipolar disorder can be drawn.