What's even more amazing is that the placebo can also work when people aren't deceived - when they know that what they're taking isn't medicine.
In a new study, psychologists show that this strange phenomenon can be used as a simple way to reduce stress, at least in the short term at moderate stress levels.
"Exposure to long-term stress can impair a person's ability to manage their emotions and cause significant mental health problems. So we're excited to see that an intervention that requires minimal effort can still lead to significant benefits." explained psychologist Jason Moser of Michigan State University (MSU).
MSU psychologist Darwin Guevara and his team prescribed a placebo to a group of 32 volunteers and offered no treatment to another group of 32.
All 64 participants reported experiencing prolonged stress during the COVID-19 pandemic. Their levels of stress, anxiety, and depression were measured before, at the midpoint, and at the end of the two-week trial.
The catch is that the placebo group knew they were getting pills without active ingredients. They were instructed to take the inert tablets with plant fibers 2 times a day and had to fill out a daily questionnaire about adherence to taking the tablets.
Incredibly, those who took the placebo had reduced stress, anxiety and depression compared to the group who did not take the placebo, even though they knew that what they were taking was not real medicine.
Because the sample in this case was small, Guevara and his colleagues caution that more work needs to be done to see if the results hold across cultures and age groups and over longer periods of time.
It is not yet fully understood how this brain trick works.
"Our data suggest that the effects of non-deceptive placebos on affective outcomes cannot be attributed solely to clear expectations. Other researchers have suggested that non-deceptive placebos may operate through mechanisms such as implicit expectations, conditioning by prior experience with active treatment, and embodied cognition," Guevara and team write in their paper.
Whatever the exact mechanisms, the researchers suggest that using a placebo to treat people experiencing moderate stress may help prevent them from worsening more severe conditions.
"A remotely administered non-deceptive placebo has the potential to help people struggling with mental health issues who would otherwise not have access to traditional psychiatric services. This ability to remotely administer non-deceptive placebos greatly increases the potential for scale-up," Guevara points out.
Other researchers argue that there is not yet enough evidence for the use of placebos for treatment, as such studies that confirm their effectiveness are small and too short-term.
This makes placebos ideal for use as a control in clinical trials to eliminate bias, but more extensive research is needed to confirm their therapeutic value. | BGNES
