Placebos

Studies show that between 30 and 40 percent of patients report feeling better after taking dummy pills for conditions ranging from depression to high blood pressure to Parkinson’s. Even sham surgery can work marvels. In a recent study, doctors at Houston’s Veterans Affairs Medical Center performed arthroscopic knee surgery on one group of patients with arthritis, scraping and rinsing their knee joints. On another group, the doctors made small cuts in the patients’ knees to mimic the incisions of a real operation and then bandaged them up. The pain relief reported by the two groups was identical.

Wired 15.02: What We Don't Know