A Placebo Works – And You Don’t Even Have to Believe in It!

Double-blind controlled trials – representing the gold standard of proof of effectiveness – are often conducted between an active agent and an inert placebo.  And the placebos often prove to be remarkably effective.  For instance, there’s a 30% or 40% response to placebo treatment in double-blind trials in irritable bowel syndrome (IBS) or depression.  How is this so?  Probably because we think “it works because we believe we’re taking a real drug”.  In other words, there’s an element of deception.  But this may not be the case, as shown by a study reported on PLoS ONE. 

The study was done at Beth Israel Deaconess Medical Center, Harvard Medical School.  Eighty patients with IBS (70% were female) were enrolled in the study.  Their average age was 47, with scores on the Rome III IBS scale over 150.  They were randomly assigned to one of two groups for the 3-week study.  One group took placebo pills twice daily, and the other group took no pills, but received the “same quality of interaction with healthcare providers” as the first group.  The placebo pills were labeled “placebo pills made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes”.  The patients were told that they didn’t even have to believe in the placebo effect – just take the pills.  (This was certainly full disclosure!)    

By the end of the trial, almost twice as many patients taking the placebo reported adequate symptom relief compared with control group (59% vs. 35%).  The placebo-takers also doubled their rates of improvement on symptom-severity scales to a degree roughly equal to that seen with powerful IBS medications.

The researchers concluded: “Placebo administration without deception may be an effective treatment for IBS.  Further research is warranted . . . to elucidate whether physicians can benefit patients using placebos consistent with informed consent”.  Good luck with that!  A survey has shown that many physicians already use sham interventions to harness the placebo effect in their practice.  But it’s highly unlikely that they could be persuaded to make full disclosure.