The use of placebos in clinical trials for acute schizophrenia.

This review examines the scientific and ethical justification for the use of randomized concurrent placebo-controlled trials in the treatment of acute relapse in chronic schizophrenia. A literature search was conducted, and the national regulatory authority was consulted. Many placebo-controlled studies of acute or chronic schizophrenia are being published and it is the official position of both the Canadian and US regulatory authorities that such studies are required for both scientific and ethical reasons. The specific strengths and limitations of placebo-controlled studies are reviewed. Examples, drawn from Canadian studies, are presented to illustrate their benefits. It is concluded that the use of placebos in the particular situation of acute or chronic schizophrenia is ethically and scientifically justified. It forms an essential component of a comprehensive drug evaluation for new antipsychotic medications.