• antipsychotic agents;
  • bipolar disorder;
  • chlorpromazine;
  • clozapine;
  • haloperidol;
  • lithium;
  • mania;
  • olanzapine;
  • risperidone;
  • thioxanthenes

Introduction: An important consideration in treating acute mania is the promptness with which a chosen therapy can bring symptom amelioration. This article reviews the available published data from controlled, blinded studies regarding the latency of responses to antipsychotics in patients with acute mania. Methods: Articles for this review were obtained from a search of the Medline database (1966–1999), using the following keywords and phrases: antipsychotic, atypical, bipolar disorder, mania, neuroleptic, typical. The bibliographic sections of articles gleaned from this search were used to direct further inquiries. Results: Although information regarding the onset of action of antipsychotics is limited, we discovered data for four typical and three atypical antipsychotics. Drugs with the fastest onsets include haloperidol, risperidone, and olanzapine, with onsets appearing in 2–6 days. Chlorpromazine and thiothixene were at the slowest end of the continuum, with onsets of 2 weeks or longer. Data regarding pimozide are mixed, with some studies showing an onset equivalent to that of the ‘fast’ compounds and others showing one similar to that of the ‘slow’ compounds. Conclusions: Choice of therapy should consider not only efficacy and safety, but also onset speed. Atypical antipsychotics appear to offer safer, faster, and more effective therapies.