http://www.jems.com/news_and_articles/columns/Acosta/

the_science_of_self_healing.

html;jsessionid=B4F84463578C979DD36CA9AD74B1A045

Post-script:  There's a great study that was done in 2005 at the University of Michigan on the placebo effect (Journal of Neuroscience, August 23, 2005  http://www.med.umich.edu/opm/newspage/2005/placebo.htm)  and pain. We've always known that placebos worked…which is why they're always ruled out in double-blind studies. What we didn't know is how…what architecture responds and is responsible for the pain relief. Their study pointed to the specific brain sites that were activated by imagery alone and simultaneously relieved pain.  

This is one more pearl of evidence for Verbal First Aid.