forgetfulpenguin
Active Member
http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.2435.html
http://arstechnica.com/science/news/2011/10/is-the-placebo-effect-partially-caused-by-cannabinoids.arsPlacebo analgesia is mediated by both opioid and nonopioid mechanisms, but so far nothing is known about the nonopioid component. Here we show that the specific CB1 cannabinoid receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (rimonabant or SR141716) blocks nonopioid placebo analgesic responses but has no effect on opioid placebo responses. These findings suggest that the endocannabinoid system has a pivotal role in placebo analgesia in some circumstances when the opioid system is not involved.
I should mention that this was only a fairly small study, and more work needs to be done in the area to fully flesh out this idea. Rimbonant can also have effects that are not all mediated through CB1 receptors, as I found out during the course of my Ph.D. But it is a neat little study, and one that expands our understanding of the pharmacology of placebos, to the degree such a thing is possible.