Lithium and
valproate are well recognized as mood-stabilizing medications. However, a significant number of patients with
bipolar disorder do not respond to or cannot tolerate the side effects of these drugs. As a result, a search for safer and more effective mood stabilizers for the treatment of
bipolar disorder is ongoing.
Antipsychotic medications have long been used as adjunctive
therapy in combination with mood-stabilizing medications. Although conventional
neuroleptics (also known as typical
antipsychotics) such as
haloperidol or
chlorpromazine are effective
antimanic agents, they do not appear to have any efficacy in treating comorbid depressive symptoms. Furthermore, typical
antipsychotics are associated with a number of well-known side effects, such as extrapyramidal symptoms and
tardive dyskinesia. Mood-stabilizing effects have recently been reported for a number of newer "atypical"
antipsychotics that have a broader spectrum of efficacy and better safety profiles than the typical
antipsychotics. The results of several clinical trials suggest that atypical
antipsychotics, including
risperidone,
olanzapine,
ziprasidone, and
quetiapine, are effective for the treatment of acute
mania, and open-label studies suggest that atypical
antipsychotics may have long-term mood-stabilizing effects.