In Brief: When expectation fails
When expectation fails
Treating the physical symptoms of people with Alzheimer's disease is difficult because they cannot easily identify or explain their needs. An experiment reveals another problem. Any treatment is likely to be less effective for them, because they lose the benefit of the placebo response.
The study compared hidden and open administration of a painkilling drug to 28 patients with Alzheimer's disease and 16 healthy controls matched for age and sex. All had veins on the back of the hand punctured for blood samples on two consecutive days. This often causes a burning sensation that is treated with lidocaine, a local anesthetic.