Can a placebo still work if you know it’s a placebo?
You probably know the placebo effect: You take a pill with no active ingredients but feel better because you believe you’re taking something that will help.
But what happens when you know the pill is a placebo?
A recent study found that healthy older adults who knowingly took placebo pills for three weeks reported lower stress and showed improvements in short-term memory and physical performance.
“Placebos don’t contain active ingredients, but that doesn’t mean the response to them isn’t real,” says Dr. Andrew Bryant, a neuropsychologist with Aurora Neuropsychology. “Our expectations can influence how we perceive symptoms and respond to an experience, which may help explain some of what the researchers observed.”
What did the study find?
The study included 90 healthy older adults who were randomly assigned to one of three groups.
Some participants took inactive pills after being told they contained ingredients that could improve well-being. Others took the same inactive pills but were told upfront that the pills were placebos. A third group took nothing.
Three weeks later, researchers looked for changes in participants’ cognitive and physical abilities and psychological well-being.
Those who knowingly took placebos stood out in two areas. They reported lower stress than both other groups and showed improved short-term memory compared with those who received no treatment.
How can a known placebo work?
Believing you’re taking an active treatment isn’t the only factor that may contribute to the placebo effect.
Researchers explained to participants who knew they were taking a placebo that it could produce real responses even without active ingredients. They also told participants a positive attitude wasn’t necessary.
“The placebo effect involves complex interactions between the brain and body, and we’re still learning how those processes work,” Bryant says. “You don’t necessarily have to convince yourself that a treatment will work to experience a response.”
Researchers don’t yet know what caused the changes observed in the study and cautioned that it was small, lasted only three weeks and produced modest, varied results.
What does the study mean for your brain health?
The findings don’t suggest a placebo can prevent or treat memory loss. The study involved healthy older adults, not people with mild cognitive impairment, dementia or other neurological conditions.
“This is an interesting study, but it doesn’t change what we know about supporting brain health,” Bryant says. “Regular physical activity, adequate sleep, a nutritious diet, and staying socially and mentally engaged remain important as we age.”
If you notice persistent or worsening changes in your memory or thinking, don’t assume they’re a normal part of aging. Talk to your health care provider about your symptoms.
