Scientists Show How Sugar Pill Eases Pain

It may be enough just to think about an aspirin, according to US scientists. Ponder painkillers, and the brain begins to release the natural chemicals that ease away the pain.

A team at the University of Michigan report in the Journal of Neuroscience today that they have the first direct evidence of the machinery behind the so-called placebo effect. In large clinical trials, many patients who receive the placebo, or sugar pill, rather than the drug under trial will report an improvement, simply because they believe they have had an effective medicine. The research shows this may not be a trick of the mind.

Jon-Kar Zubieta, of the university's molecular and behavioural neurosciences institute, said: "We were able to see that the endorphin system was activated in pain-related areas of the brain, and that activity increased when someone told them they were receiving a medicine to ease their pain. They then reported feeling less pain."

The scientists made scans of the brains of 14 healthy young men, while making painful injections of concentrated salt water into their jaw muscles. During one scan, the volunteers were told they would be given a painkiller. In fact, they were given a placebo.