Atypical antipsychotics in the treatment of bipolar affective disorders

Antipsychotics are commonly used in the treatment of bipolar affective disorder. The use of conventional antipsychotic agents, though effective as antimanic agents, is associated with a number of limitations such as their acute side effect profile and their unsufficient mood stabilizing activity. In addition, exposure to conventional neuroleptics poses a risk for the development of tardive dyskinesia, especially in mood disorder patients, Growing evidence suggests that the novel, so-called atypical neuroleptics may offer a number of advantages in the treatment of bipolar disorder, including their thymoleptic activity and minimal risk for acute and long-term extraypyramidal symptoms. Clinical experience with clozapine and olanzapine as mood stabilizers suggests greater antimanic than antidepressant properties, while risperidone may have greater antidepressant properties with some liability for triggering or exacerbating mania. The mood stabilizing properties of further atypical drugs are currently under investigation. This review focuses on the use of atypical antipsychotics in the treatment of bipolar disorder. We also present an overview concerning potential pharmakokinetic interactions based on the cytochrome P450 enzyme system when antipsychotics are combined with other mood stabilizing compounds. In conclusion, atypical antipsychotics should come to play an increasingly important role in the acute and long-term management of bipolar disorder, but there is a clear need for further controlled trials in this indication.