Intended for healthcare professionals

Rapid response to:

Views & Reviews

The thinking doctor’s guide to placebos

BMJ 2008; 336 doi: (Published 01 May 2008) Cite this as: BMJ 2008;336:1020

Rapid Response:

Will patients given placebos be expected to benefit from a placebo effect?

Pitroff and Rubinstein may think they have devised an ethically acceptable framework in which a clinican could justifiably prescribe a placebo, but it is based upon a false premise.

The primary benefit of a placebo comes from the patient's belief that he will receive a biologically-active intervention and the consequent expectation of clinical benefit. Once he is aware that the doctor wishes to give him something that is therapeutically inactive, there will be no expectation of benefit and the placebo response will be expected to significantly diminish, or indeed disappear altogether.

In essence, once a patient is aware he is taking a placebo, he cannot be expected to show a placebo effect. The only way to morally justify Pitroff and Rubinstein's approach would be on the basis of study evidence that has demonstrated that patients derive benefit even though they know they are taking placebos, and as yet there is no such evidence.

Competing interests: None declared

Competing interests: No competing interests

06 May 2008
Peter J Flegg
Consultant physician
Blackpool FY3 8NR