Study Finds Thrill-Seekers More Sensitive To Placebo Effect
Well, this suggestion is based on a study by McGill University researchers Montreal, Canada, which has shown that thrill-seekers enjoy a stronger placebo response than people with more restrained personalities.
Neuroscientist Petra Schweinhardt has revealed that this conclusion was arrived at after testing 22 male university students.
She agrees that it is too early to prescribe phoney pain treatments based on personality tests.
The researcher, however, insists should larger trials confirm her team's findings, they may help pharmaceutical companies avoid testing experimental drugs on people with strong placebo responses.
During the study, Petra and her colleagues injected a pain-inducing saline solution into the left and right legs of willing volunteers for 20 minutes.
"It's a dull pain, a dumb pain, it's aching, it's annoying," New Scientists quoted her as saying.
She revealed that before the study started, all participants were told that the research team were testing an experimental analgesic cream - really just skin lotion.
With a view to making the rouse more believable, the researchers said that they would test one leg with the treatment and one leg with a non-medicated lotion.
"We really told them the whole story in order to counteract any doubts in the treatment," Schweinhardt says.
The researchers asked the participants to rate their pain across both trials, and observed that the difference amounted to the placebo response.
Not everyone got pain relief from the placebo, but those that did score higher on tests that gauge sensation-seeking personalities. Such characteristics explained about a third of the differences in placebo responses between volunteers.
"The fact that they show a pretty strong correlation between a personality trait and strength of placebo response, I do find interesting," says Jon Stoessl, a neurologist at the University of British Columbia, who has studied placebo response in patients with Parkinson's disease.
He, however, adds: "If whatever condition you're suffering from is severe on one occasion and really a minor nuisance on another occasion, that could affect the degree of placebo response."
Schweinhardt agrees that motivation could play an important role in the placebo response.
Paul Enck, a neuroscientist at the University of Tübingen in Germany, says this is the first study to conclusively link personality traits and placebo response.
"I would guess that at least some of these personality traits assess why people participated in this study. People like to be paid for something they enjoy rather than something they do not," he says.
A research article on the study has been published in the Journal of Neuroscience.