The placebo effect may work in reverse - Everyone has heard about the placebo effect. If one takes a sugar pill, but believes it is a drug, it tends to work. Now a new study suggests that the reverse may also be true.
In the study, pain levels fluctuated widely people with his belief that receiving or not a potent analgesic, remifentanil, even though the dose remained unchanged throughout the experiment.
In fact, increased levels of pain shortly after participants were informed that it had discontinued the drug, which experts call the "nocebo" effect.
The findings suggest that doctors may have to take into account patients' beliefs about treatment, whether positive or negative, experts say.
"Our study provides evidence that expectations about the effect of the drug in critically influence its clinical efficacy," said lead researcher Dr. Ulrike Bingel, Department of Neurology, University Medical Center Hamburg, Germany .
"We found that positive expectations about treatment substantially improved (doubled) the benefit analgesic remifentanil. On the contrary, a negative expectation about treatment completely abolished the analgesic effect of remifentanil," he said.
"Interestingly, this same pattern was found in the activation of brain areas that we either have to do with the intensity of pain," Bingel said.
The study, which also involved researchers from the University of Oxford in the UK, appears in the Feb. 16 edition of Science magazine Translational Medicine.
For the study, Bingel equipment provided to 22 healthy volunteers the opioid analgesic remifentanil, and then assessed its effect on changing patient expectations about treatment.
First, participants were placed inside an MRI brain scan, and they placed an intravenous line used to administer the medication. Then the researchers applied heat to the leg of each volunteer, to the point of causing pain, and set the heat to a level at which each participant rated their pain initially in 70 of 100. At the same time, remifentanil provided to volunteers, but they said they did.
As expected, when the potent drug was effective, the average level of pain reported by participants declined slightly, falling 66 points to 55 on a scale of one hundred points.
The researchers told the volunteers that remifentanil had begun (although I had been getting). The result: average pain levels of the participants were reduced dramatically, to 39 points.
To evaluate the effect "nocebo" Bingel team then informed volunteers who were going to stop the medication and may begin to feel pain again. This was a lie, and that continued to administer the same level of analgesic.
At that time, the pain levels reported by the volunteers turned up to an average of 64 points, that is, the pain was as intense as if they had not received any analgesic.
At each stage of the experiment, the MRI scans showed different brain activity in response to the varied expectations of pain or pain relief volunteers, the researchers said. Specifically, people who were prepared to believe that they received the analgesic, the difficult areas of the brain activated that pain signals reach the brain or spinal cord, researchers said.
Bingel believes that the data "opens a new avenue of research" that linked the drugs to the personalities and expectations of patients in the context of specific medical conditions.
The findings also have implications for clinical practice, he said. "We believe that the beliefs, expectations and prior experience with drug therapy should be evaluated more systematically integrated by [doctors] to optimize the overall outcome of treatment."
Another expert agreed.
Dr. Fatta B. Nahab, assistant professor of neurology at the Miller School of Medicine, University of Miami, said the study shows that the expectation of the patient may have an impact on results.
"What this shows is that doctors need to do a good job of educating patients about their treatments, and also limit false or negative expectations," he said. "If we do, our results would be much better, and I think that patients would be more satisfied with their treatments."
The findings could also point to ways of using the brain to better treatments.
"People have raised the possibility of suppressing the placebo effect," said Nahab. "This is our first indication of how we could do. If we can get into some of these regions and see if we can change, maybe we can improve the effectiveness of any drug or treatment, and this is actually a big part of this work."
