How Effective Are Antipsychotics in Treating Schizophrenia?

Overview of schizophrenia and atypical antipsychotics used in the treatment of schizophrenia.

Are antipsychotics really effective in treating schizophrenia? And are the newer atypical antipsychotics better than the older ones? Here's the research.

Effectiveness of Antipsychotics in Treating Schizophrenia

A large number of studies have been done on the efficacy of typical antipsychotics and atypical antipsychotics.

The American Psychiatric Association and the UK National Institute for Health and Clinical Excellence recommend antipsychotics for managing acute psychotic episodes and for preventing relapse. They state that response to any given antipsychotic can be variable so that trials of different medications may be necessary, and that lower doses are to be preferred where possible.

The prescribing of two or more antipsychotics at the same time for an individual is reported to be a frequent practice but not necessarily evidence-based.

Some doubts have been raised about the long-term effectiveness of antipsychotics because two large international World Health Organization studies found individuals diagnosed with schizophrenia tend to have better long-term outcomes in developing countries (where there is lower availability and use of antipsychotics) than in developed countries. The reasons for the differences are not clear, however, and various explanations have been suggested.

Some argue that the evidence for antipsychotics from withdrawal-relapse studies may be flawed because they do not take into account that antipsychotics may sensitize the brain and provoke psychosis if discontinued. Evidence from comparison studies indicates that at least some individuals recover from psychosis without taking antipsychotics and may do better than those that do take antipsychotics. Some argue that, overall, the evidence suggests that antipsychotics only help if they are used selectively and are gradually withdrawn as soon as possible.

Atypical vs Typical Antipsychotic Medications for Treatment of Schizophrenia

A phase 2 part of this study roughly replicated these findings. This phase consisted of a second randomization of the patients that discontinued taking medication in the first phase. Olanzapine was again the only medication to stand out in the outcome measures, although the results did not always reach statistical significance, due in part to the decrease of power. Perphenazine again did not create more extrapyramidal effects.

A subsequent phase was conducted. This phase allowed clinicians to offer clozapine which was more effective at reducing medication drop-outs than other neuroleptic agents. However, the potential for clozapine to cause toxic side effects, including agranulocytosis, limits its usefulness.

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Sources:

  • American Psychiatric Association (2004) Practice Guideline for the Treatment of Patients With Schizophrenia. Second Edition.
  • The Royal College of Psychiatrists & The British Psychological Society (2003). Schizophrenia. Full national clinical guideline on core interventions in primary and secondary care (PDF). London: Gaskell and the British Psychological Society.
  • Patrick V, Levin E, Schleifer S. (2005) Antipsychotic polypharmacy: is there evidence for its use? J Psychiatr Pract. 2005 Jul;11(4):248-57.
  • Jablensky A, Sartorius N, Ernberg G, Anker M, Korten A, Cooper J, Day R, Bertelsen A. "Schizophrenia: manifestations, incidence and course in different cultures. A World Health Organization ten-country study". Psychol Med Monogr Suppl 20: 1-97.
  • Hopper K, Wanderling J (2000). Revisiting the developed versus developing country distinction in course and outcome in schizophrenia: results from ISoS, the WHO collaborative followup project. International Study of Schizophrenia. Schizophrenia Bulletin, 26 (4), 835-46.
  • Moncrieff J. (2006) Does antipsychotic withdrawal provoke psychosis? Review of the literature on rapid onset psychosis (supersensitivity psychosis) and withdrawal-related relapse. Acta Psychiatrica Scandinavica Jul;114(1):3-13.
  • Harrow M, Jobe TH. (2007) Factors involved in outcome and recovery in schizophrenia patients not on antipsychotic medications: a 15-year multifollow-up study. J Nerv Ment Dis. May;195(5):406-14.
  • Whitaker R. (2004) The case against antipsychotic drugs: a 50-year record of doing more harm than good. Med Hypotheses. 2004;62(1):5-13.
  • Prien R, Levine J, Switalski R (1971). "Discontinuation of chemotherapy for chronic schizophrenics". Hosp Community Psychiatry 22 (1): 4-7.
  • Lieberman J et al (2005). "Effectiveness of antipsychotic drugs in patients with chronic schizophrenia". N Engl J Med 353 (12): 1209-23. doi:10.1056/NEJMoa051688.
  • Stroup T et al (2006). "Effectiveness of olanzapine, quetiapine, risperidone, and ziprasidone in patients with chronic schizophrenia following discontinuation of a previous atypical antipsychotic". Am J Psychiatry 163 (4): 611-22. doi:10.1176/appi.ajp.163.4.611.
  • McEvoy J et al (2006). "Effectiveness of clozapine versus olanzapine, quetiapine, and risperidone in patients with chronic schizophrenia that did not respond to prior atypical antipsychotic treatment". Am J Psychiatry 163 (4): 600-10. doi:10.1176/appi.ajp.163.4.600.


next: Atypical Antipsychotic Medications for Treatment of Schizophrenia
~ back to articles on the schizophrenia library
~ all articles on schizophrenia
~ all articles on schizoaffective disorder
~ thought disorders homepage

Last Updated: 27 March 2017

Reviewed by Harry Croft, MD

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