Trick or treatment
Dr. Harriet Hall has a fascinating article on the placebo effect over at eSkeptic:
We not only know placebos “work,” we know there is a hierarchy of effectiveness:
- Placebo surgery works better than placebo injections
- Placebo injections work better than placebo pills
- Sham acupuncture treatment works better than a placebo pill
- Capsules work better than tablets
- Big pills work better than small
- The more doses a day, the better
- The more expensive, the better
- The color of the pill makes a difference
- Telling the patient, “This will relieve your pain” works better than saying “This might help.”
Dr. Hall also discusses four factors that explain how the placebo effect works — expectancy, motivation, conditioning, and endogenous opiates. Also in the article, a section on whether animals respond to placebos, and a summary of the ethics of the matter.
In this great video, Dr. Ben Goldacre, author of Bad Science, explains the role of the placebo effect in medical research.