"Placebo Nation"

I read this Newsweek story last week, but I find that it's been rattling around in my head ever since. Provocative stuff. Below is an excerpt and a link to the full essay.

http://www.newsweek.com/id/120094

Placebo Nation: Just Believe
By Sharon Begley

New research hints at the surprising power of the placebo effect

People are incensed at the very thought that the (often expensive) meds they rely on might be 21st-century versions of the magic feather that Dumbo, the flying elephant, was told would make him airborne.

No one is saying "positive thinking" can cure cancer, or that patients should throw out their pills, let alone that illnesses that respond to the placebo effect are "all in your head."

But there is no denying the drumbeat of studies on the therapeutic power of placebos. Over the years they have been shown to relieve asthma, lower blood pressure, reduce angina and stop gastric reflux. An inert solution injected into the brains of patients with Parkinson's disease reduced muscle rigidity about as well as standard drugs.

In a bizarre finding, sham surgery of the knee, in which patients got sedation and an incision but no actual procedure, relieved the pain of osteoarthritis better than actual arthroscopy -- and produced an equal improvement in joint function, scientists reported in 2002.

And last month an analysis of clinical trials of a range of antidepressants found that, except in the most severe cases, placebos lifted the black cloud as well as meds did.

Rather than railing against that finding or pretending it doesn't exist, what we should be doing is learning how brain activity that corresponds to the expectation of cure translates into clinical improvement. As Dan Ariely of Duke University says, "It's not that medicines are crummy, but that the placebo effect is so powerful."

There have been clues about the source of that power. In Parkinson's disease, studies find, the expectation of getting better raises brain levels of the neurochemical dopamine, whose shortage underlies Parkinson's, and normalizes the pattern of firing in a region of the brain where aberrant firing causes the loss of motor control. When the placebo effect relieves pain, it releases natural opioid-like molecules in the brain that have analgesic effects like morphine.