First, do no harm
Researchers are discovering more about the power of placebos, but it’s alternative health providers who have fully incorporated them in their business model. Does evidence-based medicine need to pay more attention to contextual effects?
A leading science journal reported in 2007 the case of a young man with plummeting blood pressure who was admitted to hospital shaking and sweating. He said that after an argument with his girlfriend he had taken 29 antidepressant pills, which he had been given as a participant in clinical trial of a new drug. Even after six litres of saline drip, his condition was worrying. Then it was discovered the pills contained no active ingredients: he had taken an overdose of placebos. In less than 15 minutes he had recovered and his blood pressure was back to normal.
Not all contextual effects in medicine are this spectacular, but they are part of many recoveries: 25% of men with erectile dysfunction reported significant improvement after taking an inactive substance they believed to be Viagra. In some cases of arthrosis of the knee, traditional surgery and ‘placebo surgery’ both reduce pain to a comparable degree. The quality of life of some patients with Parkinson’s disease has been improved by faking stem cell implantation. Even babies are receptive to placebos, as are most domestic and farm animals.
But the context in which a treatment is administered can have negative consequences: the young man who took the antidepressants had suffered a ‘nocebo effect’. In 1983 the British Stomach Cancer Group told 411 prospective recipients of a new chemotherapy treatment that nausea and hair loss were possible side effects. Over 30% suffered hair loss and 56% reported vomiting before the treatment began. All they had had was a placebo.
