Updates from Derren Brown and the Enigma Crew

“Want to maximize the placebo effect? A good way to do this, according to a new study, is to tell someone they have a decent chance of getting the real treatment instead of a fake pill, but keep them guessing. In the study, Parkinson’s disease patients given a placebo after being told they had a 75 percent chance of receiving an active drug produced significant amounts of dopamine, a chemical key to the brain’s reward system that is scarce in the brains of patients with this disease. But no dopamine response occurred in patients given placebo after being told they had a 25 percent, 50 percent, or 100 percent chance of getting real treatment.

The findings show that expectations directly regulate the power of the placebo effect by kicking the brain’s reward system into gear, probably not just in Parkinson’s patients but in a number of different illnesses, such as chronic pain and depression, according to Dr. A. Jon Stoessl of the Pacific Parkinson’s Research Center in Vancouver, British Columbia, and his colleagues. “The greatest form of reward is really to get better, so expectation of improvement is akin to expectation of reward,” Stoessl explained in an interview.

Stoessl and his colleagues first demonstrated a relationship between the placebo effect and dopamine release in Parkinson’s patients nine years ago. Given dopamine’s role in the reward system, he explained, “perhaps it would be important for the placebo effect in other conditions.” In the current study, the researchers used PET scans to examine whether patients’ expectations of getting an active drug would be related to the amount of dopamine released in their brain after they took a placebo. They randomly assigned 35 patients to be informed that they had a 25 percent chance, 50 percent chance, 75 percent chance, or 100 percent chance of receiving an active drug. But all were given inactive placebo. “There was a substantial amount of dopamine released, but only when the stated probability was 75 percent,” Stoessl explained. “What that means is when you’re told that the outcome is certain, that there’s a 100 percent chance, you don’t activate reward pathways. At lower probabilities, you just don’t think there’s much chance, so you don’t activate the reward system either.”"

Read more at Reuters (Thanks @XxLadyClaireXx)