Gone But Not Forgotten
- Aug 18, 2002
- Reaction score
www.guardian.co.uk/life/dispatch/story/ ... 44,00.htmlPlacebo pills can make you happy
Thursday June 16, 2005
Just as placebos can bring relief from pain, researchers have found that they can affect our emotions too. Predrag Petrovic of the Karolinska Institute in Sweden, reporting in this week's Neuron, has shown that if placebos are used to relieve anxiety, they affect the same brain circuitry as when relieving pain.
Previous research has shown that people's expectation of relief plays a big role in the effectiveness of placebos. In his experiment, Petrovic induced this expectation by giving his volunteers an anti-anxiety drug to reduce their unpleasant perception of pictures including mutilated bodies. The volunteers were then given an antidote, and told that it would restore the unpleasant perception.
The next day, the volunteers were told that they would receive the same drugs. But instead, they received a saline solution as a placebo. Their brains were also scanned during these experiments using functional magnetic resonance imaging (fMRI).
Petrovic found that the placebo reduced the volunteers' ratings of the pictures by 29% as well as reducing the activity in the brain's emotional areas. In addiction, the placebo increased brain activity in the part where activity increases when placebos have been used to relieve pain.
Those people who expected the largest effect showed the largest changes in activity in the emotional and modulatory areas of the brain.