# s-pnei: placebo: increase in placebo perceptions (only in the US)

<< (..) analysis of clinical trials conducted since 1990 found that the increase in placebo responses occurred only in trials conducted wholly in the US; trials conducted in Europe or Asia showed no changes in placebo responses over that period >>

http://www.mcgill.ca/newsroom/channels/news/american-placebo-255973

Alexander H. Tuttle, Sarasa Tohyama, et al. Increasing placebo responses over time in U.S. clinical trials of neuropathic pain. PAIN, 2015; 1 DOI: 10.1097/j.pain.0000000000000333

http://www.ncbi.nlm.nih.gov/pubmed/26307858