Seroquel (quetiapine)

Efficacy: acute and outpatient setting

Data from clinical trials involving patients with schizophrenia or bipolar disorder show that the atypical antipsychotics have similar efficacy profiles [1].  Seroquel has proven efficacy in treating the positive and negative symptoms of schizophrenia [2,3] and in controlling the mania associated with bipolar disorder [4].

Data from a randomised, single-blind study comparing Seroquel, olanzapine and risperidone in patients with schizophrenia indicated that these atypical antipsychotics have similar efficacy in short-term treatment as measured by Positive and Negative Syndrome Scale (PANSS) total scores [5].

pptSee slide for more information

Furthermore, a meta-analysis of 22 randomised, short-term (4-8 weeks) controlled trials of Seroquel, olanzapine, risperidone, aripiprazole and ziprasidone demonstrated that when the PANSS positive and negative subscale scores were analysed no significant differences were seen between the atypical antipsychotics [6].

pptSee slide for more information

In the longer term, data from a combined analysis of four open-label extension phase trials showed that significant improvements from baseline in Brief Psychiatric Rating Scale (BPRS) total scores with Seroquel occurred at 6 months and at each timepoint up to 4 years.  Thus, early improvements in symptom control with Seroquel are maintained during long-term treatment [7].

pptSee slide for more information

Bipolar mania
The early efficacy seen with Seroquel in patients with schizophrenia is also demonstrated in patients with bipolar mania.  Combined data from two randomised, placebo-controlled monotherapy trials showed Seroquel was significantly superior to placebo as early as Day 4 in patients with bipolar mania [4].

pptSee slide for more information

Efficacy conclusions for Seroquel

  • Seroquel demonstrates efficacy in improving the positive and negative symptoms of schizophrenia [2,3]
  • The efficacy of Seroquel is maintained in the long-term treatment of patients with schizophrenia [7]
  • Seroquel demonstrates efficacy in patients with bipolar mania [4]


  1. Tandon R, Fleischhacker WW. Comparative efficacy of antipsychotics in the treatment of schizophrenia: a critical assessment. Schizophr Res 2005; 79: 145-155.
  2. Copolov DL, Link CGG, Kowalcyk B. A multicentre, double-blind, randomized comparison of quetiapine (ICI 204,636, 'Seroquel') and haloperidol in schizophrenia. Psychol Med 2000; 30: 95-105.
  3. Riedel M, Muller N, Strassnig M, Spellmann I, Engel RR, Musil R, Dehning S, Douhet A, Schwarz MJ, Moller HJ. Quetiapine has equivalent efficacy and superior tolerability to risperidone in the treatment of schizophrenia with predominantly negative symptoms. Eur Arch Psychiatry Clin Neurosci 2005; 255: 432-437.
  4. Vieta E, Mullen J, Brecher M, Paulsson B, Jones M. Quetiapine monotherapy for mania associated with bipolar disorder: combined analysis of two international, double-blind, randomised, placebo-controlled studies. Curr Med Res Opin 2005; 21: 923-934.
  5. Sacchetti E, Valsecchi P, Regini C, Galluzzo A, Cacciani P, Agrimi E, Mencacci C. Comparison of quetiapine, olanzapine and risperidone in schizophrenia. Poster P.2.122 presented at the 17th Congress of the European College of Neuropsychopharmacology, Stockholm, Sweden, October 9-13, 2004.
  6. Tandon R, Jibson MD. Comparing efficacy of first-line atypical antipsychotics: no evidence of differential efficacy between risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole. Int J Psychiatry Clin Pract 2005; 9: 204-212.
  7. Kasper S, Brecher M, Fitton L, Jones AM. Maintenance of long-term efficacy and safety of quetiapine in the open-label treatment of schizophrenia. Int Clin Psychopharmacol 2004; 19: 281-289.


Quick Links

Page Tools