Placebo effect ‘starts in the spine’

“Research suggests that the placebo effect works, in part, by blocking pain signals in the spinal cord from arriving at the brain in the first place”, The Times reported. The newspaper said the spinal cords of 15 healthy volunteers had been scanned while they received laser ‘pinpricks’ to their hands.

Placebo study

An inactive cream was applied to both hands, but sometimes the subjects were told it was analgesic. The volunteers told they had been given a pain relief cream reported feeling 25% less pain and showed “significantly reduced activity in the spinal cord pathway that processes pain”.

This interesting small study highlights the powerful ‘placebo effect’ of suggestion. The 25% improvement in pain scores seen from the placebo effect is similar to the response seen in other studies on active versus placebo pills. This suggests that at least part of the effect can be explained by a neurological mechanism that is prompted by a belief in the effectiveness of a treatment.

The interest for scientists here is the imaging technique that made high resolution scans of this hard to reach area of the brain possible, and the confirmation that some sort of messaging from the brain to the spinal cord plays a role in pain control.

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