Scientists have found they can reliably predict which patients suffering from chronic back pain will respond to a sugar pill.
People with particular brain structures and psychological traits were found to enjoy a significant reduction – up to a third – in the intensity of their pain.
And the benefits were enjoyed even when the patients were told they weren’t receiving pharmaceuticals.
“Their brain is already tuned to respond,” said senior study author A. Vania Apkarian, professor of physiology at Northwestern University Feinberg School of Medicine.
“They have the appropriate psychology and biology that puts them in a cognitive state that as soon as you say, ‘this may make your pain better’, their pain gets better.”
There’s no need to fool the patient, said Dr Apkarian, whose remarks are taken from materials on the university website.
“You can tell them, ‘I’m giving you a drug that has no physiological effect but your brain will respond to it’,” he said. “You don’t need to hide it. There is a biology behind the placebo response.”
In the study, 68 chronic back pain patients were randomised into two groups. In one, subjects didn’t know if they got the drug or the placebo. Researchers didn’t study the people who got the real drug.
The other study arm included people who came to the clinic but didn’t get a placebo or drug. They were the control group.
Of the 43 patients in the placebo group, 24 reported a reduction in the intensity of their pain, averaging about a 20 per cent drop. This pain relief persisted during the six-week period, even when people weren’t taking pills.
The subjects whose pain decreased as a result of the sugar pill had a similar brain anatomy and psychological traits. The right side of their emotional brain, the limbic system, was larger than the left, and they had a larger cortical sensory area than people who were not responsive to the placebo.
The chronic pain placebo responders also were emotionally self-aware, sensitive to painful situations and mindful of their environment.
“Clinicians who are treating chronic pain patients should seriously consider that some will get as good a response to a sugar pill as any other drug,” Dr Apkarian said. “They should use it and see the outcome. This opens up a whole new field.”
Brain abnormalities trigger pain after back injuries
Dr Apkarian isn’t new to pain prediction. In 2013, he published a study that showed abnormalities in the structure of the brain predispose people to develop chronic pain after a lower-back injury.
The findings of the placebo study have major implications in pain treatment, notably in the context of the opioid epidemic that has killed tens of thousands of Americans in recent years.
But they also show promise for Australians.
According to peak body Painaustralia, pain is the most common reason that people seek medical help – yet it remains one of the most neglected and misunderstood areas of healthcare.
One in five GP consultations involves a patient with chronic pain and almost five percent report severe, disabling chronic pain.
As Dr Apkarian noted, the findings have several potential benefits: prescribing non-active drugs rather than active drugs is desirable because most pharmacological treatments have long-term adverse effects or addictive properties.
By eliminating the placebo effect from drug trials, fewer people would need to be recruited as lab rats with subsequent savings for patients and the healthcare system.