Even when we take a real
painkiller, a big chunk of its
effect is delivered not by any
direct chemical action, but by
our expectation that the drug
will work. Studies show that
widely used painkillers like
morphine, buprenorphine and
tramadol are markedly less
effective if we don't know we're..."
http://mobile.nytimes.com/2016/01/10/opinion/sunday/a-placebo-treatment-for-pain.html
