If You Believe a Placebo Reduces Negative Feelings, It Might
Believing in a placebo's power can reduce neural measures of emotional distress.
Posted Aug 09, 2020
Believing that a drug-free nasal spray (containing an innocuous saline solution) has the power to reduce negative feelings can reduce both self-reported stress levels and decrease emotional-distress-related brain markers—if someone is educated on how the placebo effect works, a new study demonstrates.
These findings (Guevarra, Moser, Wager, & Kross, 2020) on the stress-reducing power of a "non-deceptive placebo" were published on July 29 in the journal Nature Communications.
"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," first author Darwin Guevarra, a Postdoctoral fellow at Michigan State University (MSU), said in a news release.
For this study, a team of researchers from Dartmouth College, MSU, and the University of Michigan set out to investigate if giving people non-deceptive placebos—which are given with full transparency that the treatment is "drug-free" and does not contain any active ingredients—could change how the brain responds to emotional information and distress.
This research springs from a hypothesis that it may be possible to harness the power of the placebo effect without being deceptive by educating participants on the evidence-based science related to how placebos work, and highlighting that, if someone believes in the potency of the placebo effect, that a placebo can have psychological benefits.
"This verbal suggestion approach leverages one of the primary psychological mechanisms through which placebos operate: a person's expectation that their condition will improve after receiving a treatment," the authors explain.
In a two-part experiment that included control groups, the researchers investigated if telling one group of participants, "the nasal spray was a placebo that contained no active ingredients but would help reduce their negative feelings if they believed it would," might affect self-reported emotional distress and stress-related brain activity. In both arms of this study, the control group was not educated on the placebo effect before using the saline solution nasal spray.
Interestingly, the researchers found that people who were told that the placebo would reduce negative feelings—if they believed it would work—self-reported less emotional distress after using the saline solution (placebo) nasal spray.
Notably, participants who believed in the placebo effect also showed reduced electrical brain activity associated with distress within a few seconds of taking the nasal spray. In both cases, the control groups—who were not instructed to believe in the power of the placebo effect—did not experience significant stress-reduction benefits after using the saline spray.
In their recent (2020) paper, Guevarra et al. sum up the significance and future implications of this research:
"Non-deceptive placebos may offer a cost-effective intervention to help manage a host of clinical disorders and nonclinical symptoms; however, it is important first to establish that their beneficial effects go beyond self-report measures and lead to positive changes on objective biological markers. Our findings demonstrate an objective non-deceptive placebo effect on a neural biomarker that is relevant for emotion regulation and conditions characterized by emotional distress. Future research should examine the generalizability of these findings to other populations, domains, and biomarkers."
"These findings provide initial support that non-deceptive placebos are not merely a product of response bias—telling the experimenter what they want to hear—but represent genuine psychobiological effects," co-author Ethan Kross, professor of psychology at the University of Michigan and director of the world-renowned Emotion and Self-Control Lab, said in the news release.
"Placebos are all about 'mind over matter,'" co-author Jason Moser, professor of psychology at MSU and principal investigator of their Clinical Psychophysiology Lab, added. "Non-deceptive placebos were born so that you could possibly use them in routine practice. So rather than prescribing a host of medications to help a patient, you could give them a placebo, tell them it can help them, and chances are—if they believe it can, then it will." (Moser and Kross have collaborated extensively over the years. See "Silent Third-Person Self-Talk Facilitates Emotion Regulation")
In light of the coronavirus pandemic, the researchers are following up on this research with a real-life, non-deceptive placebo trial that will specifically address psychological distress associated with COVID-19.
Darwin A. Guevarra, Jason S. Moser, Tor D. Wager, Ethan Kross. "Placebos Without Deception Reduce Self-Report and Neural Measures of Emotional Distress." Nature Communications (First published: July 29, 2020) DOI: 10.1038/s41467-020-17654-y