A study presents physiological evidence that treatments honestly presented as placebos can still provide benefits.

When a person receives treatment, it is natural for them to expect, or at least hope, that it will provide some benefit. Sometimes this expectation alone can produce a positive effect, as often occurs in studies where participants unknowingly receive a placebo instead of actual medication.

Now, a new study finds that even when researchers tell people that what they will receive contains no active ingredients, a placebo can produce a positive neurobiological effect.

The authors conducted two experiments where participants viewed 40 emotionally charged images. Thirty of these images were negative, while ten were neutral.

In both investigations, participants in the main cohort read materials explaining the placebo effect.

The experimenters then instructed the participants to inhale a saline-solution nasal spray and informed them this was a placebo. They also told them this substance could reduce the emotional impact of the images they were about to view.

By contrast, the control group participants did not learn about the placebo effect. Although they inhaled the same spray, they were told it was meant to enhance the accuracy of sensor readings to be taken as they viewed the images.

In the first experiment, individuals self-reported the nondeceptive placebo effect on their response to the images. As the researchers expected, these participants reported a reduction in the stressful impact of the pictures.

The second experiment used EEG readings to assess changes in stress-related neural activity as participants viewed the images.

The authors saw a gradual reduction of activity during the time window in which the brain was developing an emotional response to an image.

This suggests the nondeceptive placebo was physiologically calming the participants.

Co-author Ethan Kross of the University of Michigan in Ann Arbor, Michigan, says, “These findings provide initial support that nondeceptive placebos are not merely a product of response bias — telling the experimenter what they want to hear — but represent genuine psychobiological effects.”

The study’s lead author Darwin Guevarra, postdoctoral fellow at the University of Michigan, sums up the study’s takeaway:

“Just think: What if someone took a side-effect-free sugar pill twice a day after going through a short convincing video on the power of placebos and experienced reduced stress as a result? These results raise that possibility.”

The researchers now want to explore the use of nondeceptive placebos for reducing COVID-19-related stress using real-life trials.

Medical reference: Medical News Today