Who is More Likely to Experience a Strong Placebo Effect?

A new study finds that people who have a better handle on their negative emotions may be more likely to experience a stronger placebo effect. Researchers at the University of Luxembourg found that participants who were better at interpreting negative events in a positive light felt more relief from a placebo pain-relieving cream.

The placebo effect has traditionally been viewed in a negative light; however, within the last decade, researchers have investigated the placebo effect itself and found that placebos can trigger real biological changes in the body, including the brain.

“Brain scans showed researchers that specific regions in the brain react when a person receives a placebo and as a result experiences less pain,” said researcher Dr. Marian van der Meulen, a neuropsychologist at the University of Luxembourg.

“The regions in the brain that process pain become less active, which demonstrates that the placebo effect is real. But the psychological mechanism is still very little understood, and it is unclear why some people show a much stronger placebo response than others. We suspected that the way we can regulate our emotions plays a role and set out to investigate this.”

“It’s important to understand that the placebo effect is not only an imagined improvement when we believe we receive a medication.”

In fact, the placebo effect not only occurs when people are given a bogus treatment, but it is a part of every medical procedure, said van der Meulen. For example, it is triggered by the presence of a white coat and other signs of medical authority. It also happens when we receive verbal suggestions of improvement and when we’ve had previous positive experiences with a treatment.

Importantly, clinicians or psychiatrists may be able to improve the outcome of a medical intervention by optimizing the contribution of the placebo effect, added van der Meulen.

For the study, the researchers used fMRI (functional magnetic resonance imaging) to investigate the associations between brain regions that respond to placebo and a person’s ability to regulate emotions.

First, the researchers assessed the participants’ ability for ‘cognitive reappraisal’, or how well they can reinterpret negative emotions. To measure this, participants were asked to look at images intended to elicit negative emotions. Their task was then to come up with ideas or interpretations that made them feel more positive about these images.

Next, the participants were put in the MRI scanner while they received painful heat stimuli on their arms. They were then told that they were being given a powerful pain-relieving cream, which in reality was just a simple skin moisturizer.

All participants reported feeling less pain after the placebo cream had been applied. Notably, however, those with a greater ability to control their negative feelings showed the largest responses to the placebo cream in the brain.  In other words, activity in brain regions known to process pain was most reduced in these participants.

The findings suggest that an individual’s ability to regulate emotions affects how strong his or her response to a placebo will be.

Next, the research team hopes to use fMRI to assess the placebo effect in elderly people. “We know that older people perceive and report pain differently than young people, yet why this is the case remains poorly understood. With improved understanding, clinicians and caretakers may be able to better diagnose and treat pain conditions in elderly people,” said van der Meulen.

Source: University of Luxembourg

Posted by Patricia Adams